For me it was a guy who tried to sell me $800 of tooth whitening services and ultimately sold me two tubes of toothpaste for $20. Once he got me to sit in his chair and talk about myself he hung on tenaciously. It was clear he had authority to mark prices down to 25% of the first price he gave and he'd give you half of that off in cash and give you the other half by doubling the product on you.
I was shocked when I walked away then the next guy asked me if I knew about the dead sea salts and I told him "Yeah, some guy put them on my hand in the mall years ago and it felt great but then 15 minutes later my hands felt dried out and awful."
You might say the guy from White Science is a brilliant salesperson, but if you look at Yelp you'll see people are generally not happy with the products and services that they get there.