As study done by the Direct Marketing Association (USA) realized that 2/3 of North American companies declare that their sales have increased during 2001, as a result of using e-mail marketing.
The medium-sized companies experienced a 59.8% increase in sales during 2001. On the other hand, the bigger companies observed a 47.1% increase in their sales, and the smaller companies a 42.6% increase. The study also revealed that 15% of all the companies total sales came from the results of promotional email marketing developments in 2001. 63% polled said that e-mail marketing was the tool clients said was most effective, meanwhile 37% said that it was an effective tool for obtaining clients. According to the Direct Marketing Association in USA, plain text is the most popular and consistent format used in e-mail marketing, 80% of people polled are using it nowadays.