I wonder how many people actually shop around - I know I didn't until I was in my mid 20's and had been driving for over a decade. I stayed with the company my parents had, and they'd been with the same company for decades before that. I think insurance, especially if you haven't really had to use it much, is very much a "legacy brand" - if it's what your parents had, it's probably what you'll have.

I'm with Geico now and love it, but before I switched I tried to maximize my discounts - paying for 6 months at a time instead of every month is a huge one, and in general trying to be a cautious and aware driver.

Also sometimes bundles can be more expensive - you might save money by bundling your car and renters insurance with one company, but they might charge twice as much for renters as a different company, so you're actually paying more than if you shopped around/had separate policies.