Apple (AAPL -1.22%) investors have been slowly coming to terms with the reality that the iPhone maker is hitting a ceiling with smartphone growth in the high-end segment, while Samsung is gallivanting in all market segments and has massive unit volumes to show for it.

We already know that Apple sold 37.4 million iPhones during the first quarter, which was enough to earn it 17.3% market share based on IDC's estimates. However, those figures are based on sell-in to the channel, but if investors consider sell-through digits, Apple is doing a little better than you think.

A tale of two market researchers
Apple recognizes revenue upon sell-in. While the majority of its sales are conducted directly through its online and retail stores, Apple's third-party distribution channel is still large and growing. That being said, Tim Cook acknowledged that even after converting iPhone units to a sell-through basis, Apple admittedly underperformed the broader smartphone market last quarter.

Samsung is the exact opposite. Most of the South Korean conglomerate's sales are conducted through its massive network of third-party retailers, with direct sales playing a smaller role. Converting to sell-through will have a bigger effect on Samsung's units.

Gartner just released its first-quarter estimates, which are based on sell-through to end users, which can be compared to IDC's sell-in shipment estimates. The overall effect is that Samsung's market share is slightly lower, while Apple gains a little.

Here are each researcher's estimates for Q1 units.

Vendor

IDC (sell-in)

Gartner (sell-through)

Difference

Samsung

70.7 million

64.7 million

6 million less

Apple

37.4 million

38.3 million

930,000 more

Sources: IDC and Gartner. Figures may not sum due to rounding.

Next up is Q1 market share.

Vendor

IDC (sell-in)

Gartner (sell-through)

Difference

Samsung

32.7%

30.8%

1.9% lower

Apple

17.3%

18.2%

0.9% higher

Sources: IDC and Gartner.

The difference isn't enough to turn the tables in Apple's favor, but it definitely adds some important context to its rivalry with Samsung.