Age of Empires Online launched in August 2011, and while developer Gas Powered Games and publisher Microsoft said that the revival of the long running RTS series was a "free-to-play" game, the truth was that players had to pay real money to get a number of extra content, including civilization expansion packs.
This week, Gas Powered Games released a major new update to Age of Empires Online. In the game's official blog, it reveals a new feature that turns the in-game Empire Points generated by players into something more. The blog post states, "They are now the currency used to purchase all in-game content such as civilizations, boosters, and vanity gear ... This change makes Age of Empires Online truly "free-to-play."
If you don't want to get Empire Points while playing Age of Empires Online, you can also purchase them with real money. This feature is now enabled on the Steam version of the game and will be added to the Games For Windows Live version sometime later. All current players will get 500 Empire Points for free and all new players will get 100 free Empire Points.
The update also adds a lot of other new content and features including a new contest for players at level 40 called Alliance Wars. There's also some new cosmetic gear and Empire Consumables to purchase, along with a lot of other changes and bug fixes.
Source: Age of Empires Online blog