Update [7/15]: The Fire Stick with HBO is out of stock, but it's still available with a $45 Sling TV credit for $15.
Ends 7/16. Prime day deal! Prime members only. Amazon has the Amazon Fire TV Stick Streaming Media Player with Alexa Voice Remote (2nd Gen) + 2 Months of HBO for $15 with free shipping on $25+ or with Prime. HBO auto-renews at $15/month (cancel anytime).
If you don't see the $15 price, click another selection, like "Fire TV stick" or "Fire TV Stick + Echo Dot", then click back to "Fire TV Stick + 2 Months HBO" to see discounted price.