The Conference Effect?

I've been looking into all the Fall tech conferences, trying to figure out which will be best to aim a BricaBox launch for, and as I was poking around on the Web 2.0 Summit site, I started wondering what effect these things had on the companies' trajectories who presented at their launch pad last year. Of all the consumer-facing web sites, Sphere, Skikkit, and Sharpcast did the best, in terms of traffic, over the past 9 months; but that's not saying much (meaning two things: firstly, that these are fairly poor traffic numbers for companies that launched in such a limelight; and secondly, Sphere has done better than this graph reveals because they're embedded in publishers' sites).

Now, BricaBox is a different app than all of these apps, so there are no apples-to-apples comparisons to make here. However, looking at this graph does make me wonder how much it really helps to participate in a launch pad.