I suggest that anybody who is interested in this should give the free trial a spin before signing up to a paid subscription... for me this is not working accurately at all, I have cleared my cookies, I have signed out of Google, I have used the spyglass feature to varify the rankings and my keywords are NOT ranked where serbook says they should be... it's too bad because I really like the tool, but unfortunately it's not even close (for me anyway)
I was in communication with the OP but it seems that once I asked them to explain why Serbook showed NO ranking in Yahoo and Bing for a keyword that is actually ranked #2 on both search engines.... well communications just came to an end.... hmmmmmmm, guess they had no explanation
Anyway, I hope others are having better luck with it, but for me this is a Fail!