I own two websites, and both of them are in the video game market. The first is SPG and my second website, which happens to be the most popular, is PS3Tag.com. I think it's pretty dumb to create tons and tons of websites. Most people that have that many websites (idk, like +10) do not take care of them, who could? And, I having that many is really not necessary. It's a much better plan to spend time on one, two, or maybe even three and build them up to the best of their abilities.
I've got about 10 but most are on autopilot. To maintain a "real" site youself is a lot of work and you couldn't really do more than 2-3 without help.
I've got about 20 but it's hard to look after them all. 2 or 3 make real money and funnily enough it's those that have had the most time spent on them =) you don't get money for nothing . . . well, not unless you're really clever
I have 3 and find that I spend most of my time on the one that makes the most money. It makes very good money, so I tend to neglect the others. I often wonder if I just had the one could I push it forward a heap faster?!?