Nintendo, Sega, Microsoft, Sony: what are their strategies during console wars that are generally unique to them. 

Hmmm...

Nintendo: Sell all units at a profit whenever possible, push forward with 1st party titles

Sega: Advertise system as better than the competition, support all hardware for as long as possible

Microsoft: Use Online features and additional extras to push forward with young men

Sony: Ensure device is simple as possible to work with for 3rd parties, have additional major use like DVD playback.

Give your own interp

Though, I think Microsoft stole Sony's additional major use strategy when they gave the Xbox One S 4K Blu-ray support and Sony didn't surprisingly.

MS seemed to really push the "we'll tell you what to like" strategy this gen. Too hard. I think that was fairly unique to them.

The original posters thing for sony is completely wrong, ps2 and ps3 where horrible to developer for and they just recently changed it with the ps4 but the xbox one is still easier to develop for (because of UWP and Windows 10) but they choose ps4 as the main platform for most games because it sold much better (makes sense)

I think Sony's strategy is engaging single player experiences. OP is right in they want a device to make it super easy to game on.

Microsoft has the strategy to push multiplayer and co-op in addition to offering one device for everything with applications and support

Nintendo obviously the original poster is right, profit profit and great games from first party.

And they we have steam. profit. sales. profit more. better sales.

While things have changed or been copied by each other over the years, I would say this pretty much covers each companies overall game plan from their first console onward, without going into too many details or mistakes.

NiN - One small step at a time when innovating high quality first party exclusives. One giant leap in innovating new hardware. Focus on children and teens. Devs, my way or the highway. Gimmick, controllers. Show how advanced in certain ways, different, and fun you are, then charge a lot for everything and make profits on margins not volume.

PS - Make good enough hardware. Have tonnes of game variety. Fill gaps with quality first party exclusives. Focus on everyone. Devs, lets try and work together. Gimmick, DVD, BluRay, Move, VR. Charge a widely affordable sum of money for the console, and sell a boat load of games and extra's at a reasonable price for each unit sold.

XB - Have the most powerful hardware off and on screen. Push online. Cater to third parties. Have a few first party exclusives just to fit in. Focus on teens and young adults. Devs, tell us what you want, support us, and we'll pay the bills. Gimmick, Kinect,(VR). Charge a reasonable amount of money for everything, especially online.

Sega wasn't just about more edgy marketing but they were proud how their hardware could come close to and in DC's case surpass Arcade quality games. SEGA in the arcades also pushed tech very far with Model 1-3 and Naomi. They also were VERY interested in innovating hardware as much as Nintendo but their approach was different. Nintendo tried to re invent the wheel. SEGA was about adding to the wheel. So Online games and services. They also dabbled in motion controls with Genesis and Dreamcast.  Shenmue was innovative in dev tools. SEGA had the right ideas but not the best timing and ways to go about it.

Microsoft? They have been clueless. 360 era well the begining of it had a group who advertised it VERY WELL. They pushed Achievments (not an innovation just stupid) and granted XBLA got indies going on consoles more. Since then MS has no direction. Just Gears Halo Forza and keep promising it's the best year with no Japanese support. MS has seemed directionless since 2010. Seems they just want to shove multiplayer in everything to justify XBL still I guess.

Sony. Same as PS2 era. Release first party games sparingly and rely mainly on 3rd and the hardware just throw more power at it and copy ideas from others and market the hell out of it. It works.Thankfully this time like PS1 PS4 is a very easy machine to program for unlike PS3 or PS3. Sure we may sell at a loss for a bit but sell in volume. It's a strategy they works for them and they don't  have to change it anytime soon. I have every console and handheld they released including the PocketStation. Since I am very old school I still can't see past just a electronics company making consoles and wierd to me they been around long enough to develop a fanbase of people who grew up with it.

Nintendo. Re invent the wheel every damn time. Do it on hardware that is is cheap to make and easy to profit from. Now innovation is good. Something different can be good. Sometimes it works out like Wii DS and other times not Wii U and VB. It doe smake them controversial. At times Nintendo just get's better than anyone. Other times they are a blind man in a china shop. I am glad they still make hardware. I still miss SEGA and Nintendo still contributes unlike Atari in the Jaguar days. 

I think it has changed over time for each company. They all got into the business for different reason. Some are still true to the orginal vision, some less so.

Nintendo

I think they got into the business purely for the love of games.

NES - N64 were all about making great games.

Gamecube was the first time they started to change things up, with massive competition from Sony, Sega, and Microsoft.

They couldn't stand toe to toe with them, and so Wii was a fly or die device.

On the mobile side, I think they had a very similar path. I think they were very scared of the PSP, and they tried something unheard of, and it worked out.

With 3DS they played it to safe, and with WiiU they went to wild.

Now with Switch, I think they are on their last legs. The strategy is to bring both the portable and home games back to a more traditional and unified device. We will see how it plays out, but I have really feel this will be their last platform.

I think at this point Nintendo is just holding on to pride. There strategy is all over the place. They went from traditional console, to crazy ideas, to even crazier idea + too close to old crazy idea, and now back to traditional. I think they are still have shifted focus from great games, to easy pick up and play, and family gaming. I loved Nintendo of the 90's and early 00's, but I really have not liked much Nintendo in the late 00's and 10's. I am excited about Switch, but don't see much going forward for Nintendo.


Microsoft

Xbox was 100% built to stop PlayStation from completely taking over the living room and starting to creep into the Windows space. They really had no strategy with Xbox. After they felt out the market with Xbox and saw the success of XBL, they really jumped behind the whole idea of online gaming.

X360 was built with online gaming and easy connection to friends fully in mind. It was also a time of MS working very hard to steal PS exclusives or at a minumum make sure they came to their platform as well. They saw great success with 360, and they grabbed a massive potion of Sony's userbase.

With XBO, they tried to make the online even more connected and social, while also bringing the great features of XBO to everything in the home. In a crap turn of events, the core gaming community, and the media brought a smear campaign against them, and they were not able to quickly turn things around. XBO has regained some respect in the market, but the early stumble hurt a lot.

Micosofts strategy has shifted from stop Sony from taking over the home computing market, to focusing on online/co-op/connectivity, to building the ultimate smart home device, and now to building a TV freindly Windows 10 device. I think they have a great strategy for the future. They will always have a place in the TV box market. Whther it is under Xbox, or it becomes part of the Surface products, people using Windows will always have a great reason to own an MS TV device.


Sony

PlayStation was a direct reaction to the way Nintendo burned the bridge. Sony's strategy with the PS1 was definitly to make a system that could offer everything that Nintendo couldn't, and get 3rd parties on board exclusively on their platform. After the massive success of PS1, Ken Kutaragi started to completely unfold his vision for the future of home computing.

With PS2 the strategy was to make a device that could do everything. Offering Linux, Online, DVD, Hard Drives, USB ports, and a vision for a connected gaming network, and IPTV, PS2 was the console that really set the vision for everything we have now, and even some things we still don't have. PS2 was an absolute beast. On the gaming side Sony took the massive success and made strong moves to broaden the gaming market even further. They dropped the price of 1st party games from $49.99 to $39.99. They innovated the control interface with Eye Toy. They built created a great test bed for online with Socom, Killzone, and Everquest, and FFXI.

Following up the massive success of PS2, Ken decided to go all out with PS3. His vision was to create a hub for the home, with all other Sony products using the same Cell CPU, and being part of a connected ecosystem. PS3 was packed with rediculous amounts of hardware, and was truly a device that could do everything. It was sold at a massive loss, and this was when the core gaming community and media first reared its ugly head. Even though PS3 was an $800+ device being sold at $499.99, it was smeared by everyone in the industry. People pushed the idea that the $599.99 premium model was the baseline for entry. They bashed the inclusion of blu-ray, and developers showed disdain towards the Cell CPU. At this point Kutaragi's vision was destroyed. PS3 quickly ditched the Linux functions, backwards compatability, and much of what made it amazing. Sony's strategy became survival, and winning back the media and core gamers. With PS3 completely gutted, but $100 cheaper, it began to gain back acceptance. Sony did what they could to try and continue the good will of PS2 with stuff like PS Move and PS Home, and in the end they had decent success, but lost a massive amount of users.

Moving to PS4 Sony decided to go straight after what the core gamers and gaming media would gush over. The strategy was to win over the extreamly jaded, and then broaden the platform from their. The focus of PS4 was to create a cheap, easy to program console, that did everything that the core and the media loved about PS3 and 360. Then once they have those people satisfied they can get back to the original vision. Slowly but surely they are adding more and more non gaming, home computing features while keeping the core and media distracted with games. Ultimately, they want the PS4 to become the defacto set top box, and the computing hub of the connected and social home. PS4 is set to battle cable and satalite companies, Windows and Mac, Andoird and iOS, Facebook and Xbox Live, Oculus and Vive. They are attempting to do exactly what Microsoft showed with XBO, but in a way that keeps the core distracted, and on their side. So far, so good, but can they keep it up?

Sony's strategy has shifted, but the vision of PlayStation is still true to Kutaragi's utopian view of the future of computing. The original PlayStation was a way to get back at Nintendo, and give Ken a platform. From their it was about making PlayStation the core of all Sony. They stumbled, and had to rebuild, and now they are back to PlayStation being the core again. PlayStation is about being the ultimate utopia of the digital world. A place were innovation is at the heart. Games can be anything, from cinimatic experiences, to family fun, online copetition, to relaxing in a fully realized VR world, and so much more. Sony's strategy is to build a virtual world, were everyone can live the life of their dreams, and continue that experience every moment of every day.

Nintendo:
NES-Snes: Build an industry, make revolutionary games. (For NES: Make sure third parties only make games for our console)
N64: Make a powerhouse of a console, use cartridges so pirates stay away, third parties will make games for us anyway, we are Nintendo after all.Keep making revolutionary games that blow peoples minds.
GameCube: Go with the flow, make a Nintendo "Playstation". I mean look at that name Game=Play, Cube=Station.
Wii-Switch: Make a system that is radically different from the competition. Don't just appeal to console games, but create new console gamers.

Sony:
PS1: Make a simple, easy to develope for system.
PS2-3: Ha, we owned you all big time with the previous system, we are Sony we are the best!!! Let's make the ultimate playstation, that plays all playstation games and other medias. That's a pain in the ass to develop for, so third parties will spend all their time making games for our system, and won't have time to make games for the competition.
PS4: Oh we really fucked up with PS3, let's make an easy to develop for system. Besides, let the other companies take risks, we'll just play it safe.

Microsoft:
Make an easy to develop for system, that has a PC-like architecture. Make it a budget gaming PC
And initially for the Xbox One: Fuck gamers!

Sega:
If a system doesn't sell fast enough, release new hardware!!

Sony: unique games, tons of exclusives, affordable high spec'd console

All I ever wanted. Nintendo and MS just miss 1 or 2 ingredients to be the whole package.

Nintendo: lack of powa
Microsoft: lack of exclusives