We already knew it was hard to get your hands on an Apple Watch. You can't buy them in the stores and if you tried to preorder more than a few minutes after the devices went on sale on April 24, you were likely to get a delivery estimate of June or later.

But now, it seems that even the lucky few who managed to get early shipment dates will have to wait as only 1 in 5 scheduled orders actually shipped in the first weekend.

According to Slice Intelligence, only 376,000 of the 1.7 million (22 percent) Apple Watches ordered were delivered to U.S. consumers last weekend, meaning that nearly four out of five customers are still waiting.

A further 549,000 watches are expected to ship between April 27 and June 11, but that leaves 639,000 or 38 percent of paid up customers who are still waiting for an email from Apple which will confirm their delivery date.

Amazingly,  62 percent of Apple Watch day-one sales were taken in the first hour of preorders. The data comes from shipping notifications sent to Slice Intelligence's panel of 2 million online consumers across the United States. Slice tracks and projects U.S. consumer spending through e-commerce email receipts.

The supply shortage is hardly a surprise. Apple products are often in short supply at launch as the supply chain strains to keep up with the demand from global Apple fans. Ahead of this month's release Angela Ahrendts, Apple's senior vice president of retail and online stores, acknowledged that "strong customer demand will exceed our supply at launch."

It's clear that Apple is trying to create an air of exclusivity around the watch and it is the first time that an Apple product hasn't been available for purchase in-store. Just to try one on, you have to make an appointment and then you buy online.

If you're not willing to wait until June or beyond there is another option. The watches are available in six select high-end fashion stores in Paris, Milan, Berlin, Los Angeles, London and Tokyo. Still, judging by the chaotic scenes at Maxfield on Melrose Avenue in Los Angeles, those supplies won't last long, so if you don't already have a delivery date you likely won't be able to get an Apple Watch until at least June, when they're expected to go on sale in Apple stores.