Northbrook, Ill.-based Allstate has owned online car insurance company Esurance for three months. The $1 billion acquisition puts it into the online insurance market dominated by GEICO and Progressive. Having an online insurance sales channel is critical because that's how people want to buy insurance these days. J.D. Power & Associates says agents write 90% of Allstate’s premiums. In the past three years, the percentage of people relying solely on online channels to obtain quotes has risen by more than 50%, to 23%, J.D. Power said.