Why not? Probably because testing IPv6 E-Commerce for 24 hours is all risk and no reward. If anything went seriously wrong, a retailer's site could have become unreachable for the day. That's a hefty price to pay for participating in what for retailers is essentially a publicity stunt, because virtually no customers have IPv6 connections they could use for shopping in an IPv6 online store. But that doesn't mean big retailers didn't benefit from the day—even if they didn't show up.
That's because the biggest technical part of the IPv6 Day testing involved things beyond the control of retailers: the Internet itself, and ISPs that let customers connect using IPv6. Most of the Internet currently uses version 4 of the Internet Protocol, which uses 32-bit IP addresses. IP version 6 uses 128-bit IP addresses, so there's lots more room to grow, and also implements other features that make IPv6 incompatible with IPv4. As a result, they have to operate side-by-side on the Internet.
Long after retailers begin offering their E-Commerce sites via IPv6, customers will need to be able to connect using either the newer protocol or the current IPv4. Most of the potential glitches involve how individual users and ISPs figure out which type of IP address to connect with.
And most of that testing can be done perfectly well using the sites of those government agencies, networking vendors, universities and newspaper publishers that did show up. Once the tests have exposed the problems, and those problems have been ironed out, then big E-tailers will have a reason to do more than dip a toe into the IPv6 pool.
In the meantime, at least a few small retailers were willing to jump in on IPv6 Day. For example, the online store for a gun shop in Tulsa, Okla., appeared to be running with IPv6 without problems. If that success can scale up to Wal-Mart, IPv6 E-Commerce will be in business.