The desire to populate

I'm new to R20 and working with 'Among the Living' scenario to get the hang of the system as I ran the game in RL a few days ago. One thing I've noticed.... on a tabletop in a room, I'm happy for the board to be empty, apart from main characters, relevant NPC's, etc. However, in R20 I have a desire to populate with board with lots of generic NPC's to add numbers and atmosphere. The opera house in AtL, I played it with an empty board, now tonight I'm filling it full of NPC's to give it a feeling of being alive, being real. Do other GM's have this problem? What's the popular tack? Obviously, this way takes a crapton longer to set up and deal with during game, but I think it makes for a better experience?

I wouldn't call it a "problem"... But it's frequently what I do as well. I think it's just a matter of preference and how much time you want to spend doing pre-game prep. I personally enjoy building detailed maps and scenes for my Roll20 games, so I do not see it as a burden. Others may not have the time or the desire to go that route but that's fine too. Whenever the players return from an adventure and go to the inn, there's always lots of NPCs milling about in the common room. Most are just there for appearances, 1 or 2 may have adventure hooks if the PCs happen to interact with them. I also use background sounds of ambient crowd chatter and music to increase the effect. I think the players enjoy and appreciate the extra effort, even if they don't always state it. Don't get too carried away though, the more you have on the screen the more it can slow down performance. And don't spend so much time fiddling around with NPCs that you neglect the real stars of the show (the player characters).