The S4 launched in late April or May, depending on the market, so it took Samsung less than two months to hit the 20 million mark in late June. The phone wasn’t even available in many smaller markets until early June.
The figures are not official yet, but the Korea Times reports that an official announcement should be made soon.
Last year’s Galaxy S3 took 100 days to hit the 20 million mark, which indicates demand for the S4 has been pretty good as it is reportedly selling 1.7 times as fast.
Samsung’s big target for the S4 is 100 million units, which doesn’t sound unrealistic at this point. The phone is relatively new and it has at least ten months of life left in it, if not more.
In related news, a recent survey of Korean iPhone users found that one third of them are planning to switch to a Samsung phone.