P H., i think its safe to disregard the last two comments because, with all due respect, by their own admission, they aren't part of the group of people who actually are spending money on paying GMs. Most of the people I know of that are paying for sessions want one thing: reliability. Everything else is a bonus. People paying for sessions are frustrated with the inherent flakiness of adult life and online play - it can be very hard to get a group together regularly. Part of reliability is security and confidence - they want to know the GM cares about their game, knows how to deal with problem players and has a process to weed them out, and caters to the players so that everyone is treated fairly, everyone is involved, and every session is fun. All the stuff about using roll20 features, and acting the part of NPCs - these will get you bonus points, people like that kind of thing when it's appropriate for you game. And there's definitely a lot of people in D&D style encounter-based games for whom the added immersion you can get from features like dynamic lighting is a big draw. But for most, these are not essential.