We'll stop short of calling these programs scams, though within each of these genres, some of them certainly are. We would caution that, at the least, affiliating with these programs tends to lead to dim prospects...

FREE HOSTING IN RETURN FOR…
allowing ad pop-ups on your site. That isn't freehosting. It's a barter, and a bad one, at that. Your site is providing a free ad content delivery vehicle for someone else. It distracts visitors' attention from your content, which is, after all, the point of having a website. Nobody likes being assaulted by pop-ups and your visitors will hold it against you, not your host. Hosting is cheap. Pay for it. It's worth a little bit of money to have full control over your site's content.

DATA ENTRY SYSTEMS
These programs have been around forever. The pitch is that, for a fee, you'll receive a master list of companies who will offer you data entry projects. Not only do you have to apply to the companies, most of these companies seldom need workers, and if they do, they employ local workers. The pay is generally not stellar, and the quantity of projects tends to be too small to generate much income. $500-700 per week in your spare time! is highly unrealistic.

PAID SURVEYS
These are simply too numerous to mention each by name. For a fee, you typically receive a list of "paying" survey sites. Hey, you can find these for free through searching for "surveys" in the search engines. And most survey systems don't actually pay in hard, cold cash. Rather, they pay you in "credits" which you can cash in for merchandise, sweepstakes entries, or even (believe it or not) coupons. Nope, you won't earn much taking surveys. Unless you're content being paid in McDonald's cheeseburgers and hand creme…

LEAD GENERATORS
Be careful about paying for leads. First, they're leads, not sales. If they do provide "leads," they're usually not pre-screened, targeted leads. Anyway, you don't need them. Create a good product and you can build an affiliate army. Most of these programs really only exist to sell your email address to bulk-rate middlemen who then sell them to marketers. Many, many marketers. "Privacy Policy" is a foreign phrase to them.