I would wager that if there were a DM who had a module ready to run, they could fill it up very quickly and get a game running within an hour. Unfortunately, DM'ing a game takes a fair amount of preparation, even if you're just running a pre-made module. With that in mind, I suspect that the number of players ready for a pick-up game _far_ exceeds the number of DM's looking for players. In fact, the number of responses each game in the LFG section gets seems to back this up. Maybe if you're looking for an instant-play game (or nearly instant, there's always going to be some delay in finding folks to play) you should find a pre-made module and DM it yourself? As a solution to the instant gratification thing, maybe the community could decide on an unofficial Roll20 IRC channel or something? It would be a place where folks wanting to chat about Roll20, or arrange games, or talk PnP RPGs or just whatever could all hang out. It wouldn't do anything to deal with abuse, links to illegal sites, etc, but it would be at enough of a distance that the Roll20 team could not conceivably be held liable.