"Think Geico has the best prices? Then you're gonna find this really confusing: Drivers who switched from Geico to Allstate saved an average of $400. Confused?..."(the number wasn't exactly $400, but it was around there)
The reason this bugs me is that the information given doesn't actually tell you which insurance company is cheaper. All it tells you is that the people who switched saved money. Well duh! Most people aren't going to switch if it's going to cost more to do so! For all we know, there may have been 10 people who switched from Geico to Allstate and saved an average of $400 (per year?) and 10 million people who switched from Allstate to Geico and saved $1000. The information given in the commercial doesn't preclude that scenario at all, but the makers of the commercial clearly want you to think that somehow the information does mean that you'd be better off switching to Allstate (maybe in fact you would be, but their statistic doesn't imply that).
I don't really care so much about truth in advertising, it just really bugs me when people try to confuse people with statistics that don't actually have any bearing on their claim.