My understanding is that you need to deliver the data with a latency measured in the range of milliseconds, and even then that might not be fast enough due to direct access. Here are a couple articles in the WSJ --

"Speed Traders Get an Edge" - Feb 6, 2014 - http://online.wsj.com/news/articles/SB1000142405270230445090...

"Firm Stops Giving High-Speed Traders Direct Access to Releases" - Feb 20, 2014 - http://online.wsj.com/news/articles/SB1000142405270230377550...