Right now players get a base amount of skulls per game, something like 15 for custom games and AI games, and 25 for player vs player matchmaking games. Winners get an extra 5 skulls. Many people have expressed frustration at the pace of getting skulls in multiplayer games (and how much more reliable it is to get skulls playing the campaign because of elite experience gained during the campaign).
It might be better for people if the amount of skulls rewarded as a base for playing a multiplayer match scaled with the escalation phases. Adding an extra 5 skulls per escalation phase would probably help people feel that losing a long drawn out game is more worth the time spent. In this example, a 40 minute game loss would give you something like 45 skulls, with 50 skulls for a win. Winning custom or AI games that go 40 minutes would get you 40 skulls, and losing that game would get you 35.
For fast decisive games, you would see about +5 to +10 skulls per game. What would people think of some kind of reward scaling based on game length?