I thought it was only the 15k prizes above gift tax but it was actually any prize for tax tracking. Lots of people balked when the SSN question came up and understandably so. In a few cases the prizes were motorcycles and ATVs and I felt bad for the people that passed them up.
The promotions systems were brand focused and most of them really did want to give away the prizes but sometimes it was tasking due to the fear of a scam.
The entries were mainly for brand focused games and brand focused gear/prizes mostly marketing focused. The system also only asked for email and the opt-in for the company/brand loot running it was un-selected. Though the brand companies did want to collect emails of people interested in the brand, they had to opt-in for that. We mainly needed emails for contacting if the user won. After winning, names/SSN/location would be asked for but lots of people weren't having it.