My two cents: I just bought TP on a whim the other day because I got the discount on the purchase price from happening to have just borrowed the Unofficial 2012
Disneyland Guide from the Library...the TP deal for a whole year cost me a whopping $4.87. I figured, why not? Might be fun! Well, after reviewing info on there, I have to conquer, as other here have stated, that TP's info indeed needs to be taken with a grain of salt.
I was at Disneyland twice very recently. 6 months and 5 months ago and both times were VERY different as far as crowds went! On my solo trip 6 months ago, everything for the week was literally walk on! No waits for
anything, I would certainly have called that a crowd level 1.
5 months ago, my trip with my family, happened to coincide with cinco de mayo and crowds were moderate to pretty horrendous at some points, with hour long waits on a lot of rides. I would say this trip was a 5 all the way up to an 9 during peak times.
Now, Looking back at my dates on TP shows that they predicted crowds to be exactly the same for both times, and they even said that the "actual" observed crowds ended up being the same.

I was THERE and witnessed them my very own self! There was nothing remotely the same about these weeks!
So yes, who really knows if TP is useful for anything at all? As I look at my dates coming up next week even, I can see that they keep changing their prediction! It was a 5 and now an 8! What the heck?! I can also throw out all predictions I want, but it doesn't actually mean anything. Although it's kinda fun to "roll with the guesses" with TP during the trip planning stages, I don't really think it's worth forking over money for this service that could be used elsewhere, no matter how little. JMO.