After reading this post, particularly the part about drops in CS:GO, I tried to think of a way in which starcraft players can be rewarded with similar drops. I think the idea is pretty out there and unlikely to ever be implemented, but it's fun to speculate.

So in Diablo 3 you get the customizable banners. In WoW you get the garrison. What do you have in StarCraft 2?

Imagine giving each player his own customizable planet. Maybe not something as big as a planet, perhaps more akin to a spaceship or a space platform as a 'staging point' for the player's matchmaking adventures. Every couple of matches the player may be rewarded with crew members or parts to equip his station with. Maybe unlock new colours for the player to paint his stuff with. Instead of awarding players with feats of strength achievements, players would be awarded with stuff for their stations. . It doesn't really affect anything in the actual game, it's just a giant collectible. When viewing another player's profile you'd see what their station looks like. It can be riddled with micro transactions for improvements to the station.

This is most likely a lot of work for little gain, but it's an 'out of the box' idea that might spark other more feasible concepts.