Maybe better would be to weight the first 50 votes or so, so if the site has rarely been submitted to HN, every 2 votes count as 3 or whatever variable weight works. The problem is that you can't give blanket +1 votes to submissions from less mainstream sites either, so initial traction might be harder to achieve anyway. I don't know if mods manually upvote some of the new content with this in mind, but yeah, in the end this second chance pool is pretty equivalent.