Do-it-yourself SN ad sales

Our kids may soon be supplementing their allowance with ads on their profiles and blogs. For a while now, anybody who has a Web page has been able to sign up for Google AdSense and make money on ads appearing on his/her page (lots of traffic certainly helps!). The new thing is bloggers and social-networking profile owners making money on ads in their pages. Here's an early version of this trend-to-be: Italy-based social site Dada.net's partnership with Google AdSense called Friend$, according to BigMouthMedia.com (part of a mostly UK-based digital marketing agency). That's what you might call opt-in advertising on the social Web. Another approach: opt-out advertising. Ning.com, host and production-tool provider for homemade social sites, is free to people who allow it to sell ads against their social-networking sites; but if they pay $19.95 to Ning, they can either be ad-free or sell their own ads in their sites' pages (see this in the San Jose Mercury News).