I’d classify it as an indicator of Holden Karnofsky’s sense of ethics, personally.
Charity Navigator also makes the claim of analyzing charities’ performance and I can’t speak to the relative quality of the two sites’ metrics, but Charity Navigator apparently only takes donations directly for itself. This is more transparent - $1 given to them is $1 to them, and $1 given to Charity X at Charity Navigator’s recommendation is $1 to Charity X. On the other hand, $1 to “Givewell and whatever charities Givewell recommends”, given to Givewell, will be divided up as Givewell pleases, and unless I’m missing something fundamental, it pleased itself to divide it $640K (Givewell) : $110K (donated) in 2009. I’ll admit to a complete lack of surprise at that.
GiveWell is ethically questionable and taking them (and their metrics) at face value is dubious wisdom. Here’s why. http://mssv.net/wiki/index.php/Givewell
They are not just a “site that collects and interprets data”, they collect actual money and disburse less of that money, to charities who are rated according to a highly questionable system, which was made up by people with little experience in charity and lots of experience in hedge funds.
Seems to me they are a self-inserted middle-man, whose business model is to leverage the human charitable impulse into an opportunity to scoop off a little or a lot of cream for their precious little selves. According to their financial statements in 2009 they took in ~$750K and gave out ~$110K. That’s quite some overhead.