I must say, I bought 10 of these from an E-bay seller, and they really made the holiday for my girlfriend and I. We went for 4 days over the august bank holiday (which was crazy busy), and didn't queue for more than 5-10 minutes for any ride (apart from crush!) with the aid of these, which was amazing.
I do wonder how long this can go on for, because surely if everybody is using these 'cheeky' fastpasses (and I saw plenty of other people with them), this is going to disproportionally affect the queues over the long term to the point where it's going to mean that all of the fastpasses are gone very early in the day, which is a bit unfair on the average park-goer. I imagine something will be done at some point.
In a way, I don't quite agree with the fact that these people are profiteering on fastpasses that are obviously obtained by dubious methods (I imagine most are blatantly stolen by CM's), but at the end of the day we pay a lot to get to Disney and spend a lot whilst there, so to get a minor advantage with the queues is worth it for me.
That and the fact that when we did try and queue for a ride normally there were plenty of rude spanish, french and german (sorry to generalise, but was true) people blatantly pushing in front of everybody else to get on the ride quicker. If that's the way they want to give themselves an advantage, then I feel better about my way.