The Microsoft corporation does business in both b2b and b2c markets. Sun Micrososytems and Oracle (both floundering next to Microsoft) are primarily b2b focussed. While Ebay's business is mostly b2c (between Ebay the company and their users), the business they enable with their service is almost all c2c, between one user and another.
Cam-to-cam. Online interaction where both parties are visible to each other via webcam. Sometimes used for simple conversations, but most often for exhibitionistic/voyeuristic remote sex. Usually seen in terms of a proposition in a chat room.
My webcam is on, any horny ladies want to join me for c2c?