Ads That Annoy Also Succeed by Adam L. Penenberg of Wired.com points out a great fact: Spam and Pop-up ads actually work, or advertisers wouldn’t still be using them.

One of the reasons they work is that the cost of doing these kinds of ads are so low, that a very low conversion rate can still actually be profitable.

In the mail-order business, you’re lucky if 2 percent of the people who receive your catalog actually buy something. But if a bulk e-mailer sends out 1 million messages for a product that he sells for $20, he only needs 0.1 percent to purchase it to earn $20,000. Multiply that by the number of bulk e-mailers and it’s no wonder a study by the Direct Marketing Association found that consumers spent $32 billion on products and services advertised in e-mail in 2003.

Still, just becuase they work for the advertisers, doesn’t mean people don’t hate them.

A study conducted by Dynamic Logic found that almost 70 percent of those surveyed had a “very negative” opinion of pop-under ads and almost 80 percent held similar views on pop-up ads that launch a smaller browser window.