According to this: http://en.wikipedia.org/wiki/Registered_Traveler the TSA allows these companies to collect and submit user information. The TSA then does the screening, and returns approval or condemnation.

It sounds like there were around 165,000 members. At $200 per person per year, that's $33M in revenue.

Apparently they raised somewhere near $100M in funding.

I wonder what their costs looked like.