Sure, there’s still the occasional ad campaign that bombs, but in this day and age of intense demographic tracking and focus group testing, I doubt there’s any long-running ad campaign that has continued to exist despite not doing its job well.
As much as I personally loathe the Liberty commercials, to the point I may vow to never purchase Liberty insurance, the Liberty ad campaign (as well as those for Progressive, Geico, State Farm, etc.) must be getting the word out and selling the product to have been running for so long now.