It's not required. There have been several people that have purchased the Sport at full retail without an AT&T account. I did the same when I purchased my Urbane 2 from an AT&T store without an account. You just have to find the right store because several will argue they can't so they can sell the plan.I'm a Project FI customer. Walked into an AT&T store to pick up the last LGWS they had in stock. They told me I could not purchase the watch without an active account with AT&T because they needed to assign the IMEI to an account number in order to sell the watch. Anyone have this issue or know if they can sell w/o an active AT&T account? Seemed strange they would turn down a full price purchase because I'm not a customer. Maybe an agreement with Google or...?
https://www.reddit.com/r/AndroidWear/comments/5u3g6a/how_are_people_buying_lg_watch_sports_from_att/