We give one point per game session (we play every other week), and then an additional point or two at the end of each major story arc. This means we level up about once every 4 months or so, which works just fine for us.
At the same time, we are playing out the fictitious history of our Meridian City setting.
We started in the late '20s with a power level 4 pulp game. We got those characters up to about PL6, wrapped up that campaign and then moved on to the late '30s with a Mystery Men campaing at PL 7. We played that out to PL9 before wrapping it up.
Right now we are in the Golden Age. It's 1942, and we're playing heroes on the home-front, starting at PL10 (and we are just about to get people up to PL11).
It's been great fun so far, and rather a success. We still have not decided if we will set the next phase of the campaign in the 50s (kind of a cold-war/atomic-horror game) or if we will go straight to the early 60s and the Silver Age.
