• by Gavin O'Malley  @mp_gavin, June 25, 2013

Though not the sexiest marketing channel, email continues to hold its own when measured by customer acquisition rates. In fact, customer acquisition via email has quadrupled over the last four years, according to new data from customer retention start-up Custora.

Driving innovation in the category is the almighty dollar, according to Aaron Goodman, lead data scientist at Custora.
 
“With U.S. e-commerce sales now topping $200 billion annually, digital marketers are getting savvier than ever,” Goodman explained.

“Organic search still leads as the largest channel for online customer acquisition,” Goodman added. “But as more retailers move toward a ‘free-to-paid’ subscriber model and rely on third parties to help drive visitors to their sites, email and affiliate channels have seen an explosion in growth over the past few years.”

Search and CPC ads are by far the highest-value customers, 54% and 36%, respectively, Custora finds.

Reflecting the rapidly changing landscape of customer acquisition, Custora also found that the “Lifetime Value” -- which refers to the amount customers spent in the two years after their initial purchase -- of customers acquired through Twitter is 23% lower than average.

Twitter’s low ranking may be attributed to the frequency of discounts offered within tweets, Custora speculates.

Also of note, the most valuable online shoppers tend to come from more rural states, because, as one might guess, they tend to have few options to buy locally. Indeed, New Mexico and Wyoming rank No. 3 and No. 4, respectively, in customer value for fashion brands.

That said, fashion brands find many of their best customers in densely populated coastal states, according to Custora. The marketing analytics vendor derived its findings from data spanning 72 million customers from 86 U.S. retailers across 14 industries.