These advertisements were so false it's hard to believe someone fell for them!
Head-On

“Head-On was actually legally forced to stop advertising their product as having any effect on you whatsoever. Initially it was advertised as a topical headache relief, but when they discovered the product was nothing but paraffin wax with a little menthol in it, the company was forced to remove any mention of what the product is supposed to do. That’s why the ads became ‘head on, apply directly to the forehead’ and nothing else” (source).
Penny “Auctions”

“Those penny-‘auction’ web sites. You aren’t ‘bidding’ on things to buy, you are placing bets to win _prizes _in a _gambling game”_ (source).
Make Up Products

“My friend is a makeup artist and has done the make up in ads for makeup brands. She says that most of the products used aren’t even by that brand. So an ad showing Maybelline’s eyeshadow palette is probably actually using really high end makeup” (source).
It Works!

“Those It Works! wraps. Well, they don’t work. They don’t ‘fat burn,’ they make you sweat. They eliminate hydration in your body under the top layer of skin. Plus, they have you wrap it in plastic wrap, that alone will temporarily tighten up your skin and make you lose a little water weight through sweating” (source).
Peter Pepoff

“Peter Popoff sells ‘Miracle Spring Water’ that he claims can create miracles such as cure diseases, cure addictions, wipe thousands of dollars of debt, and much more. That’s not a joke. He has testimonies on his informercials with people claiming they bought his spring water and had $240,000 of debt wiped the next day” (source).
Montgomery Ward

“There used to be a store called Montgomery Ward. They would send out circulars weekly. Maybe twice weekly. If you ever found something you wanted and ventured in there, without a doubt they would not have it in stock. Without fail people, this was years and years ago. At some point they went bankrupt” (source).
UHAUL

“Uhaul. Only $19.99/day? Sure, if you plan on renting the truck and sitting in their parking lot! But if you plan on actually driving it, oh, well, that’ll be $2/mile. Plus insurance. $20 a day my as–” (source).
Mattel

“Mattel. They once advertised a line of wind-up toy cars that could stick to any surface and drive upside down, sideways, etc. At least that’s what was shown in the commercial. Turned out they could only do that on a special track that was sold separately. Eleven-year-old me was very pissed and mailed them a letter about it. They sent me some discount coupons but I’ve never quite forgotten it” (source).
Aquafina

“Aquafina. Just saw a news article that they will be required to change their labeling because the water is just tap water. It doesn’t come from a spring nor is it purified”
Vinnie’s Half Price Pizza

“There’s a pizza place at the Preston market in Melbourne called Vinnies Half Price Pizza that advertises that their pizza’s are always half price. That’s not half off, that’s just the price”