Having just launched a Micro ISV (more about this in another post) I have been attempting to do some marketing. I started by searching twitter for people talking about the kind of technology my ISV does, and sending them a tweet introducing them to my website. You can see the small ripples half way along the graph. Then I got accepted into the Microsoft Silverlight Community Gallery and you can instantly see the difference.
Getting some publicity on a big site (even in a small way) seems to be delivering high traffic consistently.