According to my guru, Clark Howard, Delta is now offering free texting on gogo enabled flights:
Delta is offering passengers a way to stay connected on flights — without having to pay for Wi-Fi access.
Starting October 1, passengers can use iMessage, WhatsApp and Facebook Messenger to communicate with those on the ground, at no extra charge.
Free mobile messaging is for text use only, so the new service doesn’t support the transfer of photos or videos.
Delta said free messaging will be available on all Gogo-enabled Delta flights, including all aircraft with two or more cabins. Customers can access it through Delta’s Delta’s Wi-Fi portal page, airborne.gogoinflight.com.