From what I have seen the TP crowd predictions are meaningless.
Meaningless and, apparently, fiction.
I subscribed to touringplans.com for my August Disneyland trip. For months I tracked these dates/predictions below and received email updates on them from TP. The big one was the adjustment of Aug 20 for DCA up to a 9.8:
Aug 20 2012: DL 3.8 DCA 9.8
Aug 21 2012: DL 3.2 DCA 4.4
Aug 22 2012: DL 3.6 DCA 4.5
Aug 23 2012: DL 3.2 DCA 4.7
I took all these predictions and crowd calendar info with me on my trip.
Following the trip when I looked at their "historical" crowd calendar for these dates, their "history" had an entirely different set of "predictions" as compared to the "actuals" for three of the four days. The history makes it look like they estimated higher and reported lower.
The site now "reports":
Aug 20
Predicted: DL 6.3 DCA 8.1
Actual: DL 5.0 DCA 7.6
Aug 21
Predicted: DL 6.6 DCA 8.1
Actual: DL 3.6 DCA 7.3
Aug 22
Predicted: DL 6.7 DCA 8.1
Actual: DL 3.2 DCA 7.6
Aug 23
Predicted: DL 7.0 DCA 8.2
Actual: DL 3.7 DCA 7.9
I emailed them almost a month ago to report my confusion/disappointment and they said they would need to look into it. I haven't heard anything back.
In hindsight I admit the reality with understanding the predictions and the actual crowds really didn't matter to my overall experience -- it was simply least busy as the parks first opened and got busier all day long. My issue with touringplans.com is with paying for a service and trying to use that information only to find it's not worth anything.