Apple's Lack of Sales Data Raises Flags About Demand for Watch

Apple Inc.’s silence on demand for its smartwatch is making it harder for analysts to gauge whether the wearable gadget is performing successfully. Yet even low estimates suggest the timepiece could become a bestseller.

Estimates for unit sales for the quarter that ended in June range from as little as 3 million to as many as 5 million. Bears say shipments dropped after the first few weeks, while others say Apple Watch is in the early stages of gaining widespread consumer acceptance.