I guess we differ on opinion/experience regarding this subject.

In my experience surfers in mainstream want a place they can go, and come back to, that meets, and exceeds, their needs. They want a place they can refer other like minded people to.

If we take teddy bears as the example... many collectors, or would be collectors, would be attracted to a teddy bear site that fullfills their needs, and then some, with a collectors forum, the history of the teddybear, links to teddy bear auctions and other teddy bears stores. Children would be attracted to the "kids only" part of the site. It's more effective to make the best teddybear clearinghouse site you can, then to create 100 sites with, as you said, nothing but adsense and/or affiliate links.

It's quality not quantity that keeps the money coming in. Surfers are fast becoming aware of the fake adsense doorway sites and hit the back button real quick to see what Google thinks the relevent sites are, not what a site that tricked them to their page, with their own links thinks.

If you put the best into what you're creating, you're not only doing right by surfers that come to your site, but you're building a better internet community as well. My .0000002 cents