But yeah I take back the amazing sales comment. Now that I've sat down and done the math it looks like it would have ended around GC level sales, if it had a 5 year lifespan. 

The Saturn was a greater failure than the Wii U was. Sega totally botched the launch, the system had poor software support, and generally it had everything going wrong for it. It sold a paltry 1.36 million units in the U.S., far less than the nearly 5.5M units the Wii U sold. In Europe, it sold only about a million units, again far less than the Wii U sold in the region (about 3.5M). In Japan, the Saturn fared better than it did in the U.S., and was Sega's best-performing system in the region, selling over 5 million units, which is well ahead of the Wii U's lifetime tally, but that's still weak numbers and doesn't even come close to making up for the atrocious performance it had in the West. 

I don't share the opinion of crippling beyond repair. A new generation marks an opportunity for a reset in image and perception, so the Dreamcast had a legit chance to change Sega's fortunes. Of course this means to come strong out of the gates, but it's here where Sega failed already. The biggest IP Sega ever had, Sonic the Hedgehog, was crammed into a lackluster 3D game. It may have gotten good reviews at the time, but the market reception was that the game sucked. Reviews for re-releases of Sonic Adventure were more in line with the actual quality of the game. The Dreamcast had its chance, but it made a bad first impression that the rest of the first party lineup couldn't offset, so interest in the console waned quickly.

The Dreamcast had a terrible commercial performance. People often forget that. In the U.S., the Dreamcast had a decently strong launch period, pulling in 1.48M during the Sept.-Dec. period of 1999. But in 2000 it sold only 1.28M for the whole year, and in 2001 it sold only 1.25M. That's a total of 4 million units in a 28-month span. By the end of 2003 (or after 26 months of sales), the GameCube had sold 6.86M.

Meanwhile, Sega had a hit with the Genesis in America, but that system didn't fare as well elsewhere (Japan never cared for Sega, and Europe still didn't care for consoles much at the time). Then Sega had a string of disasters with the Sega CD, 32X, and especially the Saturn. The Saturn was a greater failure than the Wii U was. Sega totally botched the launch, the system had poor software support, and generally it had everything going wrong for it. It sold a paltry 1.36 million units in the U.S., far less than the nearly 5.5M units the Wii U sold. In Europe, it sold only about a million units, again far less than the Wii U sold in the region (about 3.5M). In Japan, the Saturn fared better than it did in the U.S., and was Sega's best-performing system in the region, selling over 5 million units, which is well ahead of the Wii U's lifetime tally, but that's still weak numbers and doesn't even come close to making up for the atrocious performance it had in the West. It did so poorly in the West that it was discontinued well before the Dreamcast was released, and barely outlived the official first-party production run of the Genesis (though it stuck around in Japan until 2000). Not only did the Saturn sell about 30% fewer units globally than the Wii U (it would have been even worse if it wasn't for Japan picking up some of the slack), Sega did not have a successful handheld division to compensate for their flagging hardware sales. Excluding Genesis sales (which dropped off rapidly after the Saturn was released), Sega sold only about 20 million consoles between 1995 and 2001, and their handheld sales were negligible.

Yeah, there's definitely a big difference between Nintendo's financials now and Sega's in the 90's. I think the Genesis was their only really successful console. Not sure how many Master Systems sold, but it was a virtual unknown in the U.S. Sega's American and Japanese divisions were often at odds with one another. That's how we got the 32X and the Sega CD at almost the same time. I don't remember ever seeing the Saturn, but I read up on it years ago. Sony announced the PS1 as about $100 cheaper, and Sega just up and surprised everyone with a summer launch out of nowhere. Retailers got angry that they weren't told about it, so the Saturn didn't get stocked in the U.S. very well at all.