I think it's perfectly acceptable to just count page loads. Sure it's not going to be an exact tally, but obviously an interest check with 150 views is getting a lot more attention than one with 15 views. Not all 150 views will be repeat visits/search bots/bots in general. The idea is just to know if nobody likes the concept, or if nobody is bothering to check it out, which would be very useful to me personally, as a current interest check I have running has only one reply, and I have no clue whether people dislike the idea, or just haven't looked.