The 500 Startups Index - 369 Companies & Counting
Last week I published the first Y Combinator Startup Index, which ranks the companies who have gone through the YC program using traffic data, Facebook monthly active users, and mobile data where it's available to determine how well each company is doing.
Update - 500 Startups head honcho Dave McClure left some helpful insights on the Hacker News comment thread related to this post.
As with the other index, there are caveats. Web traffic only tells part of the story for any company, and this index doesn't contain complete information about Facebook app usage or mobile app usage. What's most useful is seeing how these rankings change over time, so I will be updating this monthly.