Galaxy S4
Is the Samsung Galaxy S4 already the most popular smartphone? Reuters

The Samsung Galaxy S4 seems already to be in competition with its older sibling, the Galaxy S3, as the recently unveiled handset is gearing up to be another bestseller well before it's released, or even available for pre-order.

Carphone Warehouse, a popular European retailer, announced Wednesday that its pre-sale inquiries for the Galaxy S4 are quadruple the amount of interest it received for the Galaxy S3 prior to its release in late May 2012. If this report is any indication of the phone's general popularity, the Galaxy S4 could benefit greatly from following in the footsteps of its predecessor.

The Galaxy S3 has reigned as the best and fastest-selling phone in the world, having notably sold 20 million handsets in its first 100 days of release, 30 million in five months after its release, and more than 40 million units sold overall. It has been lauded as the “best smartphone of 2012” by numerous outlets. Its predecessor, the Galaxy S2, while also extremely popular, has sold about 20 million handsets worldwide.

The Samsung Galaxy S3 was unveiled on May 3 at last year's Mobile Unpacked event in London. By May 18, outlets reported that the Galaxy S3 had garnered 10 million pre-orders. Note that we are referring to pre-orders for the Galaxy S3, not just interest before the device was available for purchase in any capacity.

Carphone Warehouse has not divulged exactly how many inquiries it has received for the Galaxy S4, but notes that the period for the Galaxy S4 was just four days, March 15 through 18, as opposed to six days for the Galaxy S3, April 25 through 30 of last year. The retailer has implemented a £29 ($44) fee for interested customers to guarantee they will be able to purchase the phone once actual pre-orders become available.

Android Authority suggests pre-sale interest in the Galaxy S4 is not a precise indicator of how the phone will fare once on the market, and many consider that the high prices being projected for the Galaxy S4 may dampen its overall popularity. Rumors suggest that the smartphone could cost between $776 and $905 unlocked, depending on the country it's sold in.

"Approximate Retail Value" prices from Samsung suggest that the Galaxy S4 is worth approximately $650 in the U.S.; however, the South Korean company asserts that the ARV does not indicate how much the phone will sell for once released. Most suspect that if customers buy the phone with a two-year-contract, it will likely be priced between $199 and $299.

Samsung and mobile phone carriers alike have remained particularly quiet about prices and definitive release dates for the fourth-generation Galaxy S smartphone. The Galaxy S4 is expected to be available first in the U.S. and the UK in late April. It's slated to release in 155 countries, but many others won’t receive the smartphone until well into May. There is still plenty of time to determine more precisely interest in the Galaxy S4.