We use auto responders to automatically deliver our free quides, and e-books. They are a critical part of encouraging signups for our e-mail lists and we get new subscribers every day as a result of the material delivered by auto responder.
Sending the material manually would make subscribers wait for their material and would be very time intensive. Auto responders are a big part of automating my business.
The auto responder I use is called 1Shopping Cart. (Also known as Marketer's Choice. It offers unlimited auto responders AND ad tracking for only $29 per month.
1Shopping Cart also offers other components such as shopping cart, digital delivery of documents and software, affiliate program management, upselling and email and newsletter broadcasting.
An excellent tool I would not be without!
Garland Coulson, "The E-Business Tutor"
E-Business Tutor
http://www.ebusinesstutor.com/staticpages/index.php/autoresponder