It's gotta be insurance commercials.
First of all, they try to be humorous. Ad execs must be thinking we will choose the insurance company that makes us laugh because everyone knows catastrophic losses are not fun to think about. So get potential clients to equate insurance products, which cover disasters, with fun. Throw in some animals and a song.
Think of Liberty Insurance's Doug and the emu, or the Geico gecko. Met Life and Snoopy. Progressive Insurance and Flo.
Second, have a catchy, extremely short jingle.
"We are Farmer's, bum bah-dah, bah, bah, bah, bah, DAH!" (someone got paid to come up with this?!)
"Liberty, Liberty, Liberty!" (must have taken the songwriter days agonizing over this one.)
"American... Family... Insurance."
"Like a good neighbor, State Farm is there."
"Nationwide is on your side."
"You're in good hands with Allstate."
Third, know that in most states carrying insurance is legally (or otherwise) required so we are a captive audience. We gotta buy it, so why advertise?
Fourth, realize insurance ads are EVERYWHERE, all the time. TV, internet, radio, print. They are relentless. Ads aren't cheap which tells me these companies have extremely healthy profit margins and likely spend tons of money on advertising to expense those profits to therefore reduce taxation.
Fifth, insurance is a product you pay dearly for and hope and pray you never need to use it.
Yep, insurance ads are the worst.