Why the lack of demos. You'd think there would be a demo for every single game. There's only demos for a small fraction of the games on the store. I just don't understand this. It would be a whole lot easier just playing the demo,then having to look up game videos and research the game. Sales would also,probably increase if there was a demo for every game. I would think this would be more important for indie games,then any thing else. thoughts?

A bunch of reasons:
1. Demos cost time and money to make and put on the store
2. Demos often decrease sales
3. Demos just don't work for certain types of games (horror games and story based games most prominently)

http://www.computerandvideogames.com/416824/game-demos-halve-sales-new-data-suggests/

They cost time to make, money to host, and result in fewer sales.
In the past I've more often satisfied my curiosity of a game by playing the demo, than that a demo has convinced me to buy a game I was not sure of.

Though I remember Sony said at the PS4 reveal that every game in the store will be playable as a demo(presumably through Gaikai).

Wonder if that's still coming.

that's really surprising. you'd think it would be the other way around.

You might also want to have a look at this.

What I don't like is when they changed the design of the PSN store about a year ago. It loads noticably slower. I prefer how it was before, but I don't really spend too much time in the store so it's not a big deal.

i remember back in the day i would go to the store and buy a PS magazine just for the demo disk inside it sucks that demos never evolved much since then MS went the furthest with requiring all XBL games to have a demo but that got axed in 2013

i do like demos (havent got many on next gen so far ) but as some said more often than not it would have a negative effect on my purchase of the game but maybe those results are skewed since most of the time demos arent AAA games

I don't think it has anything to do with PSN, but more to do with the game developers.

I liked the old design too.  I understand why they changed it, wanted to distance themselves from the old store after the hacking fiasco and add a coat of gloss to make it more appealing aesthetically, however the change made it an unwieldy beast.  In the old setup I could find whatever I was looking for in seconds, now the search function is like trying to dictate the notes of someone in traction who can only communicate through a series of blinks.