Autoresponders have long been a staple of entrepreneurial content marketers, but hardly anyone in the mainstream has done much autoresponder testing yet. After running a few tests myself, and chatting with a bunch of people who've tested them, I've come up with a few guidelines for success:

1. Day & hour timing -- Just as with regular email campaigns, the time of day sent and day of week sent can make a big difference in response rates.

Unfortunately most autoresponder ASPs don't let you control timing beyond the number of days between each send. A responder that can skip weekends on demand, and only send during designated hours (either a preset time-of-day you determine, or at the hour that the original start request came in) is probably going to do better for you.

2. Staggering timing -- Most marketers begin testing either a single message per day for a set number of days, or a message per week for a set number of weeks. However, just like good renewal series, staggered timing may work even better with messages building to a crescendo of urgency around a particular event (such as a discount expiration date).

3. Supporting renewals early on -- I've heard of and personally witnessed many test results in B2B and B2C publishing where special attention during the first 30 days of subscriptions made a profound difference to renewal rates months later.

Makes sense -- your new subscribers pay extra attention to your content and open email at a higher rate during the first 30-60 days, so it's a great time to make a good impression for a longer lifetime account value. (It's a lot harder to get them to love you again once that thrill of being a new subscriber has worn
off.)

Stuff you can send includes a new reader satisfaction survey, a list of links to your Top 10 Best articles ever, a special "one month anniversary" gift PDF, and a quick personal note from the editor ("Here's my direct contact info if you have tips, comments or story suggestions").

Also if your frequency is less than daily, you might want to load up the latest issue in the autoresponder whenever you publish so newbies get something with more content value than just a welcome letter.

4. Cross-selling other products -- if someone's bought PDF 'X' in your online store, you can use an autoresponder discount coupon to market related product 'Y' to them a week or so later.

5. Change your offers. If you're doing an autoresponder series that goes for 5-7 days (such as a free ecourse to support sales of a book more substantially than a single sample chapter download would) it's awfully tempting to paste in the same offer at the end of each message. "If you enjoyed this lesson, click here to buy the whole book..."

However, varying your offer or the way you express your offer will probably pay off, just as it does with an old fashioned renewal series in the print world (step one: discount offer, step two: time limit on discount, step 3: free report offer, step 4: free report offer over, step 5: personal plea from editor, step 6: time's almost up notices....etc.).