Game Google With Cloaking
A cloaked page is a page that looks different depending on who, or what, is viewing the page. Black hat spammers will show an innocent page to a Google robot, but a more devious page to real users. Below, is an example of BlinkList gaming Google to “buy viagra”. From what I can determine, BlinkList is the one performing the cloaking, and not one of BlinkList’s users.
Here’s my search for “buy viagra” in Google:

Here’s what I get when I click through from Google:

Here’s what I get if I type in the URL manually:

Strangely, I can’t pull up a count of their backlinks because Yahoo site explorer silently redirects my backlink query to Yahoo search. Is Yahoo on to them?
BacklinkWatch tells me there are 4,489 backlinks.
I’m impressed they’re ranking with such few links for such a competitive term.
If you can offer any more insight please add to the comments.
TechCrunch has a profile on BlinkList.