Excellent question. Honestly, the simple answer is out of loyalty. I know that might sound weird in this day and age and when it comes to saving money, but I have had USAA for a long time, and have always been very happy with their services. We have two auto loans, a credit card, a bank account and our two auto policies with them. We would have our homeowners as well, but we live in FL where no one insures
.
In the course of my 12 years of driving with them, I have had five claims. Three were for no-fault accidents (two collisions and one comp) resulting in a total of the cars, and USAA took care of everything perfectly. They were quick with getting it resolved, and paid more then expected for the car. On one car, I put about 20k miles on the car from when I bought it and added over $2k in extra equipment, and they paid me $800 more for the car then what I bought it for nine months prior, as well as full purchase price for the added equipment. I also had someone slash the top of my convertible, and they paid for the replacement top in full, and the items that were stolen (sans radar detector which they explicitly do not cover in their terms). My wife had someone rear end her, and while Hertz covered it, USAA helped expedite things. All in all, USAA has paid out exponentially more money then they will ever collect from me on premiums for the rest of my life. I've never had a problem with them, and they have always been there for us.
Additionally, USAA pays out annual dividends to all members based on profitability and how much you've paid, which have been about $100 a year in the past (which does cut Geico's cost savings down to only ~$100).
So with that said, I am a loyal USAA "member".
While I have nothing against Geico, and for all I know they might be just as good, I also have no experience with them. I take that back, I had a scooter policy with them for about a year since USAA doesn't cover motorcycles in FL, and outside of paying the premium twice I had no other interactions. I do like their commercials though.
In the end, USAA has done very well by me, and it's very hard to say that about a company nowadays. Now I'm not crazy - if the cost difference was more significant I would definitely switch. But for a hundred or two a year, I just don't see it being worth it.
I did actually call USAA up earlier today. They currently don't offer a similar monthly mechanical insurance plan - just the one time payment for a fixed duration one. I might end up getting that, but I'll probably shop around first. Thanks for letting me know that Geico doesn't offer it as a stand-alone product, I doubted they did.