Raising money isn't any indication for any success but is a nice accomplishment - money coupled with the mentoring and connection from ycombinator could significantly improve the companies odds to succeed.
These numbers are vanity metrics but are still indicating a trend - companies going through ycombinator are more likely to raise money than others.
I know I would go thru ycombinator - not because of the money I could raise easily but mostly because of the alumni network, connections and access to world class mentors.
I launched Seed-DB earlier today (http://www.seed-db.com) where you can find these data points for all companies that have been through seed accelerators.
These numbers are vanity metrics but are still indicating a trend - companies going through ycombinator are more likely to raise money than others.
I know I would go thru ycombinator - not because of the money I could raise easily but mostly because of the alumni network, connections and access to world class mentors.
You could have a look at what companies raised money and what were the successful exits to date: http://www.crunchbase.com/company/y-combinator