Apple (AAPL -1.22%) impressed investors this morning by announcing that 9 million iPhone units were sold over launch weekend. That figure came in much higher than the Street expected. Analysts were looking for unit sales in the range of 5 million to 8 million. Apple didn't break out product mix, but supply constraints on the iPhone 5s suggest that many of those units may have been the iPhone 5c.

While the headline figure crushed estimates, it's important to remember that this year Apple is including two different models in its total. In all prior years when the company has launched new iPhones, it only announced unit sales for the high-end flagship. Last year's 5 million iPhone 5 units actually disappointed investors, so this year the tables have turned.

The Mac maker even took the extra step of filing a fresh 8-K with the SEC, saying it now expects both revenue and gross margin for the current quarter to come in at the high end of previously provided guidance. That puts the top line near $37 billion and gross margin around 37%. Consensus estimates are calling for $36.2 billion in revenue this quarter.

In the following video, Erin Kennedy discusses the iPhone launch weekend with Evan Niu, CFA.