First, let's think about the TechTV audience. I think it's safe to say that it ranged from novice techie to tech junkie, and they're people that can afford to buy nice stuff. That's why they had car commercials for better cars on the channel. It's a nice demographic to have.
Compare this to the G4 audience, which I'm fairly certain (judging by their message boards) is the young gamer types that can barely peck out English. Certainly a niche, but not a demographic that will make you rich.
Comcast bought TechTV to exponentially expand their audience because TechTV had a huge subscriber base on satellite and cable. However, you'd would think that they would also realize the revenue potential in a more diverse demographic.
This is where it reminds me of radio. In the early 90s, radio experimented with a format commonly called “Z Rock,” which appealed mostly to 12-24 males. A niche you could corner, certainly, but what the hell do you sell those people besides heavy metal CD's and zit cream? Not much. Needless to say, the format died quickly. It has been reborn to some degree as “Xtreme radio” as of late, but you don't see those stations making any big scores outside of the same demographic. The only thing different now is that Clear Channel and Infinity own everything, so they can segment the market because they are their own competition.
So the programming geniuses at G4 got the demographic that spends money and attracts bigger advertisers, only to piss it away to emphasize its original demographic. The rules aren't that different than they were in 90s radio. What do you sell that audience other than heavy metal (and hip hop) CD's, zit cream and now video games? What's the ROI for advertisers?
I hate to keep complaining about it, because I know nothing will change. It's just that I really feel like I lost something. I didn't watch that much TV to begin with outside of Alias and 24. Now that's all there is.