OVT is not very reliable for keyword info. Actually, although they are supposed to represent about 30% of internet searches, I have found that their #s are WAY higher than what you would find at Wordtracker. I trust wordtracker over OVT, but it does cost money. WordTracker has spam filters intact, OVT does not. You see, spammers are sending queries to SEs in an attempt to confuse the SEs into thinking folks are searching on popular terms and then clicking on a certain domain the spammer owns. This is an underhanded attempt to gain SE rankings. Google and others have not put in systems to counteract this spamming yet. Bottom line is that Wordtracker has filters in place to weed out these queries, OVT does not. Therefore, OVT results reflect all the searches, even the bogus spam queries.