Insights.

At iDfour, we encourage email best practices both in the layout of emails and the maintenance of the customer list.

We discourage sending emails to rented or purchased lists, and we advocate making the opt-out process as painless as possible. We even suggest dropping customers after a period of inactivity to boost engagement percentages and improve overall deliverability. Over the course of time, people change their email addresses and an email list naturally gathers a collection of good customers without valid email addresses. One way to add these customers back into your regular email program is with a process called email append. The appending process takes known customer information, like a person’s name and physical address and compares that information to a larger universe of compiled data built specifically for that purpose. iDfour appends many different types of information beyond just email to enhance our clients’ customer data. Demographics like household income can be easily appended to almost every address but the email match rate is much lower at around 25% for a good consumer list.

We recently did a large append and, by taking proper precautions, revived thousands of highly interested customers into our weekly send.

From a list of approximately 300,000 customers, we found over 90,000 email addresses that corresponded to a customer's physical address. The first thing we did was send an email "invitation" letting people know that we’ve added them to our list and giving them very easy opt-out instructions. Not only did that allow us to pull out uninterested recipients, we were also able to remove hard-bounces (bad addresses) before we loaded our final list. We used a different email server for the first send protecting our main server's reputation. After the first weeding-out process, we ended up with close to  85,000 emails that we could append to our customer database. Even though we found a high number of matches, there is a still a factor of uncertainty as to how reliable the email address is, so we categorized our matches according to the response of our invitation:  soft-bounce (receiving server says try again later), opened, no response, individual match and household match.

Instead of adding all 85,000 new email addresses to our 110,000 base list of emails, we slowly added the new emails into our marketing mix and gauged the response as we went. By starting small, even a terrible complaint rate for new addresses will not tip the scales with internet service providers (ISP) when delivered along with the healthy addresses in the base list. Had we added all 90M at once, the ratio of complaints and bounces to the overall send could have caused an ISP like Gmail or Yahoo to delay ALL our future emails or even block us altogether. To do this correctly, you have to think ahead and flag appended addresses in your database so they can be separated out at the reporting stage. ... And here are the numbers that tell the rest of the story.

After 2 weeks/sends we found:

• The appends that were only a "household match" (based on address only, not the individual) had the worst complaint rate at about 40 times the base. Spam complaints ran a whopping 1.8%. ISPs can start blocking a sender at as low as .3% complaints!
• The appends where the introductory email had been "opened" had a great open rate, about 2x more than the base BUT the complaint rate was also high: 14x the base for the individual matches and 28x for the household match.
• We went ahead and tested the "soft-bounce" although it's a lot of trouble for not much payoff: 10-15% bounce rate and half the open rate as the base. Also an extremely high complaint rate at 1.6%.
• As a whole, the rate of newly appended emails that were unsubscribed was 8x the base for the first week and 6x the second.
• The bounce rate is also important to monitor and was 8x the base for all of the fresh appends.
• Finally, the "opened" appends had a positive click rate (not counting click to unsub.) that was 25% better than the base names, so there are obviously some good names to be had in that category.

The email append process can be a good way to build your marketing reach but BE CAREFUL! Deal with a reputable append company. Be conservative: analyze your list and only append to your best customers and contacts, drop all bounces and avoid the less accurate "household" match. Have a strategy for deployment and watch the responses like a hawk. Remember that the complaints accumulate as the new recipients begin to realize that you are sending with some frequency, so don't just use your first week as a throttle for the rest of your sends. If you have any questions about how iDfour can help you get more from your customer list, feel free to drop us a line!