According to their FAQ
Q. Before I get a Server, what do I need to do?
A. You will need to place 1 sponsor banner rotator on your site pages, or if you run a Free Webspace Community, on your member pages. This will track visitors to your site and monitor banner CTR (click-thru rate). We will also need access to your stats page to be sure you are getting genuine traffic. This you must do for 14 days.
Q. Okay, so I have had the banner CTR monitor on my site for 14 days, then what?
A. We will review your stats and CTR and see if it is sufficient to be paid for by our sponsors. If so, it will take us 7 days to setup your FREE server .
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So they're not letting just anyone onboard, and you have to jump a few hurdles.
Probably a few smart moves on their part, but whether those smart moves will work or not in the long run is debatable.