One aspect of purchasing products online that still deters people from doing so is the need to pay via a credit or debit card. There are a few alternatives, such as pre-paid debit cards, walk-up bill pay, or money orders sent by mail, but the costs and hassles of navigating them are rarely worth the effort. The absence of an easy way to perform cash transactions online keeps a sizable amount of consumers from opening their wallets to ecommerce companies.

One quarter of U.S. households (over 30 million) — representing $1.3 trillion dollars in annual spending — is considered un- or underbanked, according to the FDIC, the Bureau of Labor Statistics and the US Census Bureau. Roughly the same percentage of U.S. households does not have a credit or debit card.

There may finally be a company to seize the market opportunity of bringing a large number of “cash only” shoppers online. PayNearMe, which first began as a service to purchase Facebook Credits for cash in retail stores, has extended its online-to-retail business model to a diverse group of ecommerce sites, including Amazon.com. The startup’s transaction process is about as seamless as making an online purchase with cash could be.

The rise of PayNearMe illustrates the convergence of ecommerce and brick and mortar retail. The cash conundrum facing ecommerce sites is a competitive advantage physical retailers are happy to have. Now, select retailers are helping their online brethren bridge the cash transfer gap.

PayNearMe offers major benefits to merchants. Gaining access to an almost trillion dollar segment of customers is one thing. PayNearMe makes it so merchants don’t have to worry about fraud, chargebacks, or held funds: cash payments via PayNearMe are guaranteed 100% good, communicated in real-time, and settled within days.

Consumers take a PayNearMe stub to a local 7-11 where the ticket is scanned into the store’s POS and paid for as though it were a regular 7-11 transaction. The online merchant is notified in real-time that the payment has been settled. There isn’t any added responsibility placed on the buyer. All he has to do is wait for his purchase to arrive at his door.

With adequate promotion across its partner ecommerce sites and through social media channels, I could see PayNearMe catching on. It offers a welcome alternative to the credit only options that permeate digital retail. I’m interested to see the depth of adoption that the service achieves. I don’t think there is going to be a middle ground. It’s either going to be a success or a failure.