Our startup was featured on Mashable last November. We didn't know anyone there, or have any connections that did. We just fell under the criteria, applied, and landed on the front page a week later.
I used to buy a weekly link on a blog with 34 times less traffic than mashable. It was generally is a pack of maybe 10-20 other links. That sent me ~10,000-20,000 per week.
Other than SEO benefit, that's very disappointing.
All the same - you're right, the traffic was low. A lot of people had thought "we'd made it" from being "Mashed", but clearly, that was anything but the truth. Still, I'll take it.
If you're curious, the post was here: http://mashable.com/2009/11/27/guestlist/