Over the past five years, the iPhone played a key role in making smartphones popular and helped drive Apple to new heights but maintaining the momentum going forward could prove to be a challenge.

According to the latest research from Strategy Analytics, Apple has generated an impressive $150 billion in revenues from the iPhone family of smartphones in the first five years following its launch in June 2007. However, the next five years are likely to prove more challenging for the iPhone as competition heats up and wireless carriers? concerns about high subsidies grows, according to a new research from Strategy Analytics.

?Since the first generation iPhone launch in June 2007, Apple with its visionary iPhone offerings has revolutionized the mobile handset industry,? said Neil Shah, wireless device strategies analyst at Strategy Analytics, Newton, MA. ?Over the last five years, Apple has built an unmatched ecosystem of apps, services and highly-optimized easy-to-use mobile phone hardware, shifting the power, momentum and demand on its side.

?This competitive advantage along with exemplary marketing techniques has helped Apple to command higher selling power and thus ability to generate industry leading revenues and profits,? he said.

?IPhone will be able to maintain some momentum in near-term with the new iPhone launch in coming quarters but in longer-term it will be challenging to sustain this growth levels with already maturing Android and fast growing Windows Phone ecosystems.?

Subsidies an issue
Strategy Analytics estimates that one-quarter of a billion iPhones have been shipped cumulatively worldwide, illustrating how popular the device is with consumers.

However, there are emerging signs that the iPhone?s next five years could get tougher.

One of those signs is the fact that mobile operators are becoming concerned about the high subsidies they spend on the iPhone to make it affordable to consumers.

?Until now iPhone has been able to attract industry-high operator subsidies support which has also been one of the key reasons for Apple?s top-line and bottom-line to grow,? Mr. Shah said.

?This dependence could soon come under pressure as operators globally are aiming to reduce their customer acquisition costs and shift the spend in favor to other slightly less costlier popular flagship models such as Samsung Galaxy SIII, Nokia Lumia 900 & HTC One X,? he said.

Competition heats up
Another factor that will likely contribute to the iPhone facing a tougher market going forward will be growing competition from the likes of Samsung and Windows Phone.

?The second biggest challenge is that the consumers are now more smartphone-cognizant and are hence aware that the iPhone UI is aging and the experience is limited and less enticing,? Mr. Shah said.

?Consumers hence have started looking outside iOS for fresher UI and user experience, for example: Windows Phone Metro UI,? he said.

For the second quarter of 2012, Strategy Analytics expects iPhone shipment volumes will be slightly lower compared with the first quarter while the Samsung Galaxy range will continue its shipment growth

Strategy Analytics expects Samsung to remain the number one handset vendor globally for the second quarter of 2012 with Nokia in the number two spot.

?Nokia will see its Windows Phone based Lumia volumes to ramp up as the vendor doubled its product portfolio as well as the global market reach adding important markets such as China, USA & Brazil but still not enough to offset the decline in Symbian smartphone volumes during Q2 2012,? Mr. Shah said.

Final Take
Chantal Tode is associate editor on Mobile Marketer, New York