I have seen this lately on one of my clients' sites. The other thing I can help but wonder about is in doing research in Compete on search referrals to various sites, suddenly much of the data is total nonsense. For example, here are some of the top terms supposedly generating traffic to a popular inbound marketing site:
medical coding
tn real estate
bankruptcy lawyer ventura ca
auto detailing boston
Or could this be the result of URL masking? Some sites results are complete nonsense, so that I can't tell that they get any legitimate search.