The press release called it a first, but the “record” 4 million pre-orders Apple received Friday in 24 hours is not quite the same thing as the record set last year by the iPhone 5c and 5S: Sales of 9 million units in the first three days.
The iPhone 6 and 6 Plus could beat that number, but it’s not going to be easy.
As Piper Jaffray’s Gene Munster pointed out in a Sept. 1 note, “significant channel fill” — i.e. shelf-stocking — was built into those 9 million iPhones. Perhaps as much as 3 million units.
Munster cautioned his clients to expect investor “noise” after next weekend’s opening sales numbers come out, given the likelihood that they won’t beat 9 million. His current estimate for first weekend sales: 6.5 million.
So how did this year’s 4 million pre-orders compare with last year’s pre-orders? Hard to say. Apple had 2 million pre-orders for the iPhone 5 in 2012, 1 million of the iPhone 4s in 2011, and 600,000 of the iPhone 4 in 2010. For the iPhone 5s/c in 2013, Apple did not announce first day pre-orders.
WATCH: The evolution of the iPhone
See also: Apple has already sold 4 million iPhone 6s
Follow Philip Elmer-DeWitt on Twitter at @philiped. Read his Apple (AAPL) coverage at fortune.com/ped or subscribe via his RSS feed.