Let's face it - LG phones have had problems with long-term use in the past. Many former phones from the company experienced the famous bootloop issue, which plagued the G4, Nexus 5X, G5, V10, and others. This was especially a problem for phones outside the warranty period. LG wants you to know that it's confident in the G6's longevity, and as a result, the company has extended the phones' warranty period to two years.
President of LG MobileComm USA, Chang Ma, was quick to point out to The Verge that the new warranty doesn't cover accidental damage like cracked screens (like HTC's Uh-Oh Protection does). It simply extends the normal warranty to two years, covering manufacturing defects - like bootloops. Fittingly enough, LG is calling this the "LG G6 Second Year Promise."
If you already own a G6, you simply have to register your device on LG's website within the next 90 days. If you're planning on buying a G6, you have 90 days after you purchase the phone to register. The first 12 months of warranty claims will be handled by your carrier (if you bought the G6 though a carrier), and after that, you'll have to contact LG for claims.
I do have to give credit to LG for doing this, if only because two-year warranties really should be the standard. Of course, those of you in the European Union have been enjoying two-year warranties on most products for a while now, but you don't see this often in the US.