In a note to investor obtained by The Street, Canaccord Genuity analyst T. Michael Walkley presented a survey which found the iPhone 5s as top-selling smartphone in the U.S., at tier-1 U.S. carriers and "a number of global channels." The survey also revealed that Apple can increase its pricing of iPhones in the future.

With this, Walkley reiterated his "Buy" rating of the stock and raised his price target to $660 from $610.

In his survey, Walkley noted that consumers showed strong tendency to upgrade their smartphones earlier to gain access to more expensive units like the Samsung Galaxy Note 3. This behaviour from users will benefit Apple in the future given that the company will launch 4.7 and 5.5 inches iPhones or the rumoured iPhone 6.

"We believe the small price differential in monthly handset installment payments between these more expensive devices and less expensive smartphones has contributed to this mix to more expensive devices. We believe these trends could also enable Apple to charge higher prices for the larger-screen iPhones given our belief consumers are somewhat less sensitive to higher device prices when installment payments are pro-rated over a 20-24 month period," Walkley wrote.

Walkley said that if these observed behaviour from users continue, Apple can charge higher for its future larger screen iPhones.

"Further, our U.S. surveys indicated tier-1 carrier customers were increasingly opting for early-upgrade programs and showed greater propensity toward more expensive high-tier smartphones when enrolling in these programs. We believe these trends could enable Apple to charge higher prices for larger screen iPhone 6 models. We believe Apple should win back meaningful high-end market share during 2H/2014 based on our belief new iPhones with larger screen sizes could create a strong upgrade cycle among Apple's loyal base."

During Apple's Q2 earnings call, CEO Timothy D. Cook alluded to a possible iPhone price hike.

"We price things that we think -- are priced in such a way that we think it's a fair price for the value that we're delivering and we make those on each thing as it gets closer time to come to market," Cook said.

However, Walkley's survey also found that iPhone 5s sales was not impressive during the March quarter when Samsung launched its Samsung Galaxy S5.

The Samsung Galaxy S5 maintained its dominance at the high end of the market share.