On many of the airlines that have Wifi, Delta has it on most of their mainline fleet, also have free ebay or amazon even if you don't get the wifi. The cost is

On many of the airlines that have Wifi, Delta has it on most of their mainline fleet, also have free ebay or amazon even if you don't get the wifi. The cost is closer to $12-15 for a long haul and as little as $5-7 for a mobile device or shorthaul or with a coupon pack.