AT&T will lose an average of $355 for each customer who signed up for DirecTV Now’s 100-plus channel “Go Big” tier during the $35-a-month promotional period, according to MoffettNathanson principal analyst Craig Moffett.

Moffett surfaced the figure, which he first reported back in early December right after DirecTV Now launched, in a new blog post (subscription required), examining the overall pay-TV subscriber metrics of DirecTV parent AT&T.

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On Friday, AT&T released a pre-earnings 8-K document to the SEC, indicating that it had grown its pay-TV base by over 200,000 in the fourth quarter, an amount driven “entirely” by its new virtual MVPD platform, DirecTV Now.

Moffett noted that the lifetime value of a traditional DirecTV satellite customer is $2,500. With AT&T’s traditional platforms, DirecTV and U-verse, not growing their subscriber bases, Moffett calculated, "The value erosion just from the positive net additions of DirecTV subscribers likely exceeds $70 million."

DirecTV ended the $35-a-month promotion on Jan. 9, restoring the tier to its $60-a-month price. It’s unclear as to how many of DirecTV’s initial sign-ups went with the “Go Big” tier, but it’s probably safe to assume it was most of them.

AT&T is set to release its full fourth-quarter earnings on Wednesday.