While we say farewell to these free-to-play titles in the next few months, we are always exploring new concepts and ways to bring great games to more players around the world. These were pioneering experiences, and we’re humbled that, over the years, so many of you joined us to enjoy the games and the community. In more than five years since most of these titles launched, how we play games has changed dramatically. These games will be live for another 90 days, after which they will go offline. So we find ourselves announcing the tough decision today that we are stopping development and winding down support for four PC free-to-play titles: Battlefield Heroes™, Battlefield™ Play4Free, Need for Speed™ World and FIFA World. On the other hand, some of our other PC free-to-play games are not as popular as they once were.

Though specific details were not given, the announcement alludes to low player counts and operating costs as the reason for the shutdowns:

Electronic Arts announced on April 15th, 2015 that several of their free-to-play titles would be shut down by July 14th, 2015.

Battlefield play4free official site