In my previous post on using email for the lead paint recalls, I glossed over how such an email might work. The problem for retailers is that many customers will have purchased several products that are affected by the recalls. The trouble of creating a separate email for each possible product (as well as for related products that aren't being recalled) is matched by the risk that customers will get frustrated with receiving a stream of messages when only a single message is needed.

It turns out that there is an evolving feature set available in a few leading email marketing tools that makes a single email possible--it's called relational tables. Actually, relational tables have been around for a while, but use among marketers has been pretty limited. I suspect that some of this is due to the fact that set-up of campaigns that utilize multiple tables can be pretty complex--sometimes even requiring marketing teams to have someone on staff who can create and maintain SQL statements. As such, through most of its history, email marketing has been about flat lists--each recipient has a single set of attributes like email address, name, age or gender. In relational tables, each recipient can have multiple attributes of the same kind.

In the case of our product recall message, retailers could use their existing customer email list, but link it to a product purchase table that contains all the products purchased by all their customers. The simplest use of relational tables would be to send one message per product, but benefit from only having to set up a single target/segment definition. An even more interesting approach would be to use a feature like Silverpop's multi-match dynamic content. MMDC takes advantage of Silverpop's ability to handle relational data but it allows every matching product record to be put inside a single message. So, if customer A bought one affected product, that person's message would contain only that single product. However, if customer B bought eight affected products, that person's message would list eight products. This is an entirely new level of personalization and something that both marketers and consumers will be seeing more and more in 2008 and beyond.