Yes, it is work sponsored and LOTS of people bike to work. The only stats I could find is that over 2200 employees (the program is only available in US and Canada) had stamps in 2011. No idea how much $ was donated. There are people who bike every day, literally. There is a gym on campus and each building has a bathroom with a shower so it's easy to be clean at work. They also set aside some fraction of available lockers to regular commuters. Social responsibility is important.

The annual BTWD is crazy; they give out schwag and have a big food area outside. They also asked which city you biked from and keep a tally. They allow bikes to be parked indoors and there were so many bikes they put bike racks and mounted http://www.cycloc.com/ in hallways. I attribute part of this to the California culture and the rest to working at a cool company.