Mobile phone users in the US have spoken - Samsung Electronics Co.'s (005930) smartphones and Google Inc.'s (GOOG) Motorola are fast narrowing the gap against rival Apple Inc.'s (AAPL) iPhone in terms of customer satisfaction.

In the recently released annual American Customer Satisfaction Index (ACSI) report, Samsung climbed seven percent from last year's results to achieve a satisfaction rating of 76 percent. Google Inc.'s (GOOG) Motorola also enjoyed an increase of 5.5 percent to gain 77 percent overall satisfaction rating. Apple's iPhone, meanwhile, slid 2.4 percent compared to last year to achieve an 81 percent satisfaction grade.

Although the Cupertino, California-based company still enjoyed top ranking with 81 percent, the weaker satisfaction rating this year only emphasizes the increasing popularity of the Korean brand smartphones even in the US. According to the ACSI report, a big factor in Samsung's increased satisfaction rating is attributed to its Galaxy S3 which was launched last May. The seven percent improvement "is the largest yet for any cell-phone manufacturer," the report added.

In terms of sales, the iPhone may have increased seven percent in the last quarter according to research company Strategy Analytics, but it is still considered the lowest gain since the product's introduction in 2007. Samsung, on the other hand, has grabbed one third of the market worldwide in the first three months of 2013, almost twice the 18 percent of Apple.

Stocks wise, Apple shares have experienced a slump of as much as 17 percent so far. Samsung shares, which are based in Suwon, South Korea, slid 1.6 percent in the same period, while valuation of Google's stocks increased 28 percent to $908.53 per share.

For its annual reports, ACSI conducts the survey among 70,000 consumer respondents. ACSI was established at the University of Michigan's Ross School of Business and is funded by ACSI LLC.