Now that Samsung's Galaxy S9 and S9+ are official, American carriers are tripping over themselves to offer launch details ahead of March 2nd pre-orders and the March 16th launch... and trade-in deals are a common theme this time around. T-Mobile, for instance, is promising $360 off the price of the S9 or S9+ if you turn in an eligible phone (typically a high-end Apple, LG or Samsung phone from the past couple of years). Verizon, meanwhile, is offering between $100 to $350 in credit if you hand in a qualifying phone from Apple, Google, HTC, LG, Motorola or Samsung. Comcast's relatively new Xfinity Mobile is getting in on the action as well, with promises of at least $200 and as much as $450.

There are other promos, as you might expect. Verizon is offering $100 off a Gear S3 smartwatch if you activate it on a 2-year plan, and promises a $150 prepaid card if you're switching networks. Xfinity Mobile, in turn, is offering a $250 prepaid card to anyone who buys a Samsung phone and opens a new line between now and March 22nd.

Regardless of who you choose, it's obvious why providers are encouraging trade-ins -- as with the S8, the S9 isn't cheap. AT&T is offering the S9 and S9+ for a respective $26.34 per month and $30.50 per month on a 30-month Next plan, which works out to $790 and $915. Verizon is pitching the duo on 24-month plans, with the S9 going for $33.33 per month ($800 outright) and its S9+ sibling going for $38.74 per month ($930). Sprint is promising very similar deals at $33 and $38 per month ($792 and $912) with two years of payments. T-Mobile may offer the sweetest deal of the major carriers so far. You can buy the S9 for $30 per month on a 24-month installment plan ($720 outright), and the S9+ for a similar monthly rate if you pay $120 up front ($840 full price).

Xfinity Mobile hasn't outlined its prices as of this writing. Those who want an unlocked model can skip all this fuss, of course. Much like on T-Mobile, you can buy the network-independent S9 for $720 up front or $30 per month for 24 months, and the S9+ for $840 outright or $35 per month.

These aren't the best bargains we've ever seen (there are no buy one get one offers, for example). Moreso than we've seen in some years, this is about encouraging loyalty in a market with stiff competition. They want you to either upgrade or make a firm commitment to dropping your existing carrier, and they're willing to spend a lot to make that happen.