How many Apple watches have sold so far?

Victor Luckerson has an article in Time about a bunch of money spent in Apple Stores:

The Apple Watch has now been available for nearly two months, and Apple’s been tight-lipped about sales so far, but that’s not stopping research firms from offering their own estimates.
Slice Intelligence provided data to Reuters showing that nearly three million Apple Watches have been sold in the US through mid-June. Unsurprisingly, the entry-level $349-$399 model of the watch has been the most popular. However, nearly twenty percent of purchasers are also springing for an extra watch band, which costs fifty bucks or more.
Estimates for the Apple Watch’s first-year sales have been all over the map, with analysts’ guesses ranging from fifteen million to more than thirty million. Apple doesn’t plan to break out Apple Watch sales specifically in its quarterly earnings report, so it may be quite a while until we get an official number to gauge the device’s performance.

Rico says it's still the iWatch to him, not that he'd buy one... (If Rico ever buys a watch, it'd be the Audemars Piguet Royal Oak, for a mere twenty grand or so.)