Verizon is rolling out a new payment plan for the iPhone 6S and 6S Plus, one that finally brings it into line with what other wireless carriers are offering.

The company will now let you trade in your old iPhone for a new one every single year. That's a major improvement over its previous stance, which forced customers to pay off their entire phone in full before allowing them to upgrade.

In our guide to buying an iPhone recently, we wrote that Verizon was one of the weaker options. Why? Because at the time, Verizon squeezed you into a 24-month installment plan. You could upgrade to a new device after two years, or you could at any time in between pay Verizon a lump sum to be freed from your old device and select a new one.

The advantage to this was that you ultimately owned the phone. But Verizon iPhone customers would be lagging on a two-year upgrade cycle, whereas Apple, AT&T, Sprint and T-Mobile all let their customers trade in their phones annually.

Now, by letting customers upgrade yearly, Verizon has caught up to its rivals. But it's also facing a crushing wave of price competition and general industry chaos as T-Mobile and Sprint released dueling promotions this week. T-Mobile is now selling the new iPhone for $5 a month, so long as you trade in your iPhone 6 or 6 Plus. Sprint is offering the new iPhone for as little as $1 a month in exchange for your old iPhone 6.

These aggressive pricing plans work because the carriers expect to make back some money selling your old phone on the used handset market. But they're also another sign of the tremendous changes that are continuing to roil the industry. On Thursday, Sprint indicated its willingness to merge with a cable company, though it said it's had no discussions with any particular firms.

Combining with a cable company would offer huge advantages to both firms: The cable business would be able to expand into the lucrative wireless market as pay-TV subscribers turn into cord-cutters and abandon the traditional TV bundle. And it would ease the pressure on Sprint, which is struggling to execute a turnaround after falling behind T-Mobile as the smallest national carrier in the country.