[pcora]

all of these can be faked. if you really want accurate information, server logs are the best. the only thing facebook or users can't block.

if facebook says you got all the clicks, use the server logs to show otherwise.

-- edit. I'm not saying that I trust facebook though. I don't.

[rixed]

Of course users can fake server logs, since Referrer info is totally up to the client. Also, I'd argue it's harder to distinguish a bot from a real user from the server logs than from js.