Were you swayed by the commercials 20 years ago?
I do advertising, and although I find the Geico ads entertaining, I question how much business they're getting from the spots.
I like "creative with a purpose." Super Bowl ads are often prime examples of "creative without a clue."
I don't recall seeing any GEICO ads years ago. I signed up with them because that's the insurance my friends had. Back then it was known as Government Employees Insurance Company, I believe.
Of course I can't be sure, but I think these ads would motivate me to try GEICO if I were looking for an insurance company. (I also love the ads where a celebrity is brought in to help customers tell their stories -- especially the one that a play on non-traditional casting, in which a male "actor" speaks the woman's lines.)
What the GEICO ads say to me is that the people who run this company are hip and believe I'm intelligent enough to get their jokes. Also, they're not afraid to be politically incorrect. On the other hand the ads are done in a way that doesn't necessarily offend those who are politically correct. The cavemen are quite likeable and sympathetic.
In general, I suspect that a lot of clever ads don't really translate into sales, but I think GEICO's have given the company a very attractive image.