"I have software that I would like to offer as a digital delivery (downloadable) product. I see that you sell some products that I can buy, and that I receive a URL to download the product. I am just wondering how you do this." -- Eric A. Dunn, Applied Training Science

The most automated approach is to have for each customer a special URL programmed to expire after 24 to 48 hours, so others won't be able to use it to get a free copy. Here are two programs that offer this functionality. Paul Galloway's Synergyx includes an excellent affiliate program infrastructure. It costs $1,595 installed on your website, and requires a merchant account and payment gateway (www.synergyx.com). DigiBuy has a fine system for selling downloadable products for $29.95 set-up fee and a fairly high 13.9% of each transaction; no merchant account is required (www.digibuy.com).

A non-automated but low-cost approach is to attach the digital software to an e-mail message or e-mail a static download URL. ClickBank includes an affiliate program and costs $49.95 to set-up plus 7% of the transaction; no merchant account is required (www.clickbank.com). PayPal requires no set-up fee and charges 2.9% of the transaction plus 30 cents transaction fee; no merchant account is required (www.paypal.com). I use a ShopSite online store to sell e-books (www.wilsonweb.com/ebooks), and when I receive notice of the transaction, I manually respond via e-mail within a few hours. I'll attach an e-book in PDF format to an e-mail message if it's small. If the e-book is too large, I e-mail a download URL with a username and password that allows entry to a password-protected download directory on my website. The danger with a fully automatic process is exposure to online credit card fraud. If you don't screen orders carefully for validity, you can get hit with costly chargebacks.