It turns out that a phablet has more things in common with tablets than just screen size. If you have a big phone, your data bills are going to be tablet-sized too.
According to research undertaken by Citrix, iPhone 6 Plus owners get through twice as much mobile data a month as their iPhone 6-owning counterparts and it's because of that bigger 5.4-inch display, which is perfect for watching video on the go.
However, as well as giving a potential explanation as to why bigger smartphones are leading to lower tablet sales, Citrix figures show that there is a direct correlation between a handset's screen size and its monthly data use.
The iPhone 6 Plus is not only using twice as much data per month as the iPhone 6, it's getting through 10 times as much data as the iPhone 3GS (Citrix still has customers using all of the older-generation iPhones).
But even the smaller iPhone 6 with its 4.6-inch display is responsible for using significantly more monthly data than any other iPhone model that preceded it (all of which had smaller displays).
The big takeaway for consumers is that if they're eyeing up an iPhone 6 Plus as their next smartphone their pockets will have to be deep as well as wide.