Never dealt with extended warranties at retailers, but I do try to buy all of my electronics with my American Express Blue card, which doubles the manufacturer's warranty up to 1 additional year. Of course I would prefer that the original warranty was 1 year as well, to get a full 2 years of protection.

I'd be willing to bet that D&M's other products (home theater receivers, etc.) have at least 1yr warranties in the U.S. If that's the case, I wonder why they're only offering 90 days on this particular product...