A merchant I feature on one of my sites has thrown up, in my eyes, some very irregular stats in comparison to other merchants on the same site. This would be fine if I was making sales from this but I'm not so I'm obviously a little concerned. For example:

June stats:
Merchant A (normal stats); Imp (866), Clicks (278).
Merchant B (irregular stats); Imp (1596), Clicks (1170) with 1 sale from this. Merchant A stats are consistent with other merchants on the site apart from Merchant B.

July stats so far:
Merchant A; Imp (97), Clicks (34).
Merchant B; Imp (768), Clicks (72). Big pageview spike since yesterday.

As you can see from these stats I don't generate a huge amount of traffic (2500 last month, my best so far) so every sale counts. Does this look odd to anyone else and how or what can I check for fishy behaviour?