I honestly believe that the Turbo Grafx 16 was totally f*cked from day one. Nothing could have saved it.
I agree %100 that the earlier marketing attempts had much more impact. The later stuff was bush league crap. In all seriousness though, you don't need a shitload of ads to sell a good product to an audience that is willing to buy it. You can just brainwash them for a while, but eventually they will move on if wasn't something they really wanted.
Have you EVER seen an add on TV for a Ferrari? I'm pretty sure they don't exist, yet they sell every car they make, often times before they are even built. Chrysler on the other hand has to pay Eminem to be in their ad, and still people aren't happy with the things.
And before some a$$hole accuses me of hating NEC systems, I'm not saying the TG was bad, but it really wasn't what people here wanted, not after the SNES was released. Sega had EA, Sonic, and the f*cking "blood code", the SNES had Mario and F Zero and Contra III, NEC had...I don't even know. What could NEC have done that would have possibly been as interesting to Americans in the early 90s and those things? I just wasn't going to happen.
And think, while the PCE was much bigger in Japan, the Mega Drive was a huge failure. If the MD was as big in Japan as it was here (ie: if they loved Hockey and really shitty fighting games as much as Americans did) would the PCE have done as well? There are only so many fans, and so many dollars to go around. Perhaps two successful systems was just the maximum possible.