Half of consumers surveyed recently by Endai Worldwide, an Internet marketing company, checked their junk mail on a daily basis. Worse yet for the spam-averse, 16% reported making a purchase from a message tagged as spam.

Half of those surveyed made a purchase in the past year in response to a marketing e-mail solicitation, including permission-based e-mail and spam.

“It reinforces what we have believed at the gut level all along, and that is that consumers will always be motivated to buy if the offer is appealing and customer-centric,” says Michael Ferranti, CEO of Endai.

E-mail marketing was most effective when purchasers recognized sender names and the offers were appealing.

Nearly six out of 10 respondents who purchased said they opened the e-mail because they recognized the sender. A quarter of purchasers said they bought because of the product offering.

More than one-fifth of purchasers said they opened the e-mail and bought something because they had been specifically interested in the item or service being offered.