Seller's Remorse Scam:
This is where an advertising company convinces you to place an ad in one of their newspapers or magazine that reaches tens of thousands of people.  For example they would then claim to be printing 3,000 copies of the posters, but would usually only print up 300.  You pay for to run your ad in 3,000 copies, but instead it goes only to 300.

Protect your business: 
Check out the circulation of the newspaper or magazine before placing an ad.  Find out where the newspapers or magazine is available and find out who reads it.