Verizon launched a buy-one, get-one-free offer on several of its high-end handsets in a move that may roil an unusually calm wireless market during the holiday season.

The nation’s largest carrier said that starting Friday, customers who buy an iPhone 8 or 8+ or a Samsung Galaxy S8 or S8+ can get a second handset free for a limited time. Both phones must be purchased through Verizon’s device payment plan, and the offer requires the activation of unlimited service.

The second phone must be from the same manufacturer as the first and be of equal or lesser value. The offer is valid both for upgrades and for users switching carriers, and the discount is applied in the form of a bell credit over 24 months.

Sponsored by Southco Inc. How To Secure 5G Equipment With Electronic Access Learn how to protect small cell enclosures from physical threats and deliver better, stronger and more reliable networks with electronic locks and access control systems. Read the Article

Notably, no trade-in is required.

The announcement comes just days after Wave7 Research published a report documenting how carriers’ “weak iPhone offers” had underscored limited competition during a normally cutthroat holiday season. T-Mobile recently dropped iPhones from its buy-one, get-one-free campaign, according to the latest report from Wave7 Research, and Sprint’s offer of $350 off an iPhone 8, 8 Plus or X with a trade-in of a recent high-end smartphone expired a few days ago.

AT&T continues to offer a buy-one, get-one-free deal on the iPhone 8 and 8 Plus, the company said, but neither the X nor the iPhone 7 are eligible for that deal.

“Some investors worried that with the T-Mobile/Sprint deal off, competition would return to the intense levels seen in 2016. This has not materialized, with no service pricing cuts, no crazy iPhone offers, and the end of Verizon’s $650 ETF (early termination fee) buyout,” Wave7 wrote earlier this week in a note to subscribers. “AT&T does have a multi-OEM BOGO that includes iPhones, but T-Mobile has no iPhone offers at all and Sprint has weakened its iPhone offer.”

Barclays analyst Amir Rozwadowski said earlier this week that “promotional activity is likely to remain relatively rational” at least through the rest of the year as carriers continue to focus on maximizing profits rather than growing market share.

Carriers have yet to offer aggressive promotions for Apple’s iPhone X, which has been in limited supply due to component problems. With less than two weeks left during the holiday season, though, it will be worth watching whether Verizon’s campaign sparks another round of carrier promotions.