Betfair have just announced that they are to change the way bets can be matched on their exchange. This is a move back to the early days of Betfair and an original concept that is actually in use by other exchanges. Full information is listed here: -
Difficult to judge the immediate impact but certainly a lot of markets will have the illusion of money in them. You are also more likely to get matched more often I would guess. On the downside some arb opportunities may have just vanished! I’ve asked the guys to put a link up in the forum so everybody can discuss in there.
It comes into force next Tuesday.