What does it profit a social media service to gain the whole world but lose its own soul?

Social media invites make me laugh. Here's one I got just this morning from bebo.com

You will like it.Click to find out whyPlease accept or reject this invitation by clicking below:[[bebo link]]

When I asked my friend if she actually sent it, she was embarrassed as heck. No, she said. She did not write "You will like it." Of course the phrase "Click to find out why" really tipped me off to how fake these invite messages actually are. Are you kidding? I know nobody except a bebo.com engineer would write something so incredibly lame. Call to actions are great, but if you're going to impersonate someone with text (the from line was sent from my friend's email address, not from bebo.com), at least make it a plausible lie.

Was hanging out with my friend Dave Zohrob yesterday and he was mentioning how the most successful social media takes its cues essentially from two places: 1) video games (which is awesome) and 2) spammers (which is just straight up evil).

I think the moral question for these sites is: At what cost viral?