Gogo is offering 15 minutes of free WiFi on Delta equipped flights. The offer is valid from June 15-30. They offer free internet from time to time and often 15 minutes is all you really need to check some email or social media. Currently you can already browse sites such as Amazon and Gilt for free the entire flight. So if you are desperate to do some online shopping there is always a way.
A great way to maximize this deal is to get 30 minutes of free Wifi by using 2 devices. First, check your email(or facebook :)) or your phone and use it for 15 minutes. Then use your laptop for the heavy browsing for another 15 minutes. You may need to use to separate email addresses to achieve this but it is a great way to get 30 minutes of free WiFi.
I fly Delta a lot and it seems as if all of their flights have WiFi these days which is great. For a complete list of WiFi equipped planes head over to Seat Guru.
More info from Gogo here.