The site was started by a regular guy, a 38-year-old from San Diego.
P.S. It apparently works with Garmin devices as well, though since I don't have one, I can't attest to that myself. Also, if you enter your flickr username, any photo you tag with "runnerplus" will show up in your profile. Talk about integration!
P.P.S. There is a section where everyone's PowerSongs are listed. A PowerSong is a song that basically plays on command (for that extra burst). It's fun to see who gets pumped to what!