Online retailers spend a lot of time and money improving their shopping experience, but relatively little emphasis is placed on the moment when the package is delivered and opened by the customer. In the entire online shopping process, it's probably the one moment filled with the most joy and positive attitude toward the retailer.

Louisville-based Packstream thinks that makes it the perfect time to introduce some upselling into the mix, and its "relationship marketing" services are designed to help retailers do that intelligently.

"You already have a captive audience," said Eric Nelson, Packstream CEO and co-founder. "I like to call this the ultimate touchpoint in permission-based marketing. They've already spent their money on the product, they're awaiting the package, and once they get it, they're going to spend another three to five minutes interacting with the brand."

Nelson said his company sees significant potential and untapped opportunity in taking the suggestive selling model that is pervasive on the web – "because you liked X, you might also like Y" – and bringing it into the physical realm.

"Most important, this is not junk mail, this is not intrusive e-mail that they're going to delete," he added. "This is going to resonate with the consumer."

The Packstream solution is a "printer-agnostic" tool that integrates directly with the retailer's e-commerce platform. Retailers are able to create marketing campaigns based on rules, then generate marketing pieces at the point of packaging. Nelson said it takes about 20 seconds from the time the fulfillment operator clicks to generate the piece and printout, which can either be a label for the outside of the package or a flier to lay inside.

One of the online retailers using the service is DormBuys.com, which sells appliances, décor and lifestyle needs for college residents. It uses the Packstream software to set rules about which groups get which marketing – for instance, students buying for themselves may get one type of message, while parents buying for their students would get different messages.

Messages contain the person's name, relevant product recommendations, abandoned shopping cart reminders, best-selling products and customer reviews.

"It's really whatever the customer's doing on their e-commerce platform, we can transition that to print output," Nelson said. "It can serve as an adjunct to a retailer's catalog, where we delve into greater personalization. And it can serve as a replacement for the catalog all together."

As for pricing, Nelson said the company is flexible and works with the retailer to find an arrangement that makes sense. That could include an outright purchase with a monthly support fee, or a pay-per-performance structure. He couldn't mention names, but said he's in "beta mode talks" with several large retailers, with a go-to-market of late Q1 in 2011.

Also in the works, he noted some significant improvements to the product in the coming months, including unique promotion codes, PURLS, personalized 800-numbers and QR barcoding for mobile device support.