That's quite a jump from $1.4M/yr on the existing contract. The article states that the last three remaining years of the old contract have been overwritten and the new terms begin immediately.
ESPN is willing to pay for inventory, especially now that it expects serious competition from Fox Sports and to a lesser extent, CBS Sports. Good news for anyone looking to renew a contract in the next several years.
http://www.hustlebelt.com/2014/8/19/6045303/explaining-the-new-mac-espn-tv-deal