I focus on 3 websites but i pay main focus with one i operate for a large university the other 3 feed on it.
I've had times when I was running a bunch of sites, but have found that I make more money when I focus on a smaller number of sites and build quality content. I own a bunch for domains for potential development, but a handlful of sites account for most of the income. If you find the right niche(s), fewer is better. RichM
450 sites most of them user generated content! I setup the sites, people make the grow!! and I dont have to lift a finger!!
Number of sites to be managed entire depends on the time a particular person has . According to my opinion a person should launch a site if he or she is interested in that niche and has thorough knowledge in that topic