Using introductory offers to woo new customers and then gradually escalate rates once they're good and settled is not a bad business model. A study from the Texas Office of Public Insurance Counsel reveals why. The study found that almost 60% of drivers rarely or never shop auto insurance policies. The study also found that a driver who switched insurers after eight years would save an average of 19%. The study only examined auto insurance, but the authors of the study said the pattern could be used with other lines of insurance, too.