Non-paying members have to look at the advertising, which generates revenue.
Not nearly as much income as a Gold member pays. It's pretty much pennies.
You can't know for sure how much money the site gets from ads per traffic, etc. Surely they get more per person from paying members, but then paying members also get other features. If you really think that being a free member is such a better deal than paying, I don't understand why you're a paying member.
Thanks, bsrasmus, I should have been clearer on that point.
Yes, I'm talking about an optional maximum time per move that you would specify when setting up a challenge in Live Chess. You would not be forced to use it.
Potential opponents would see the per-move time listed in your challenge (and could filter it in their "seek" specifications), and decide whether or not they would accept a game on this basis.
Maybe this would cut down substantially on the number of your challenges accepted, but I would actually seek out games like this because I know I couldn't be stalled for a long period. That being said, I personally only play long games (typically 30 | 3) so I'm particularly vulnerable to being stalled.