A few highly addictive browser-based MMO management games came out in the early/mid 2000s. OGame, Travian and Inselkampf were three I spent some time in. On to

A few highly addictive browser-based MMO management games came out in the early/mid 2000s. OGame, Travian and Inselkampf were three I spent some time in. On top of the simple clicking to maximise your holdings in-game, there was an additional layer of alliance/guild participation and meta game much like EVE Online. You tended to spend more time outside the actual game: discussing strategy, diplomacy and building tools.