NEW YORK: Uber, the beleaguered ride-sharing platform, has gained more millennial customers at a faster rate than any other company in the US over the past year.

According to YouGov BrandIndex, the public perception research firm, Uber's millennial customer base climbed 8.2 percentage points from the first half of 2016 to the first half of 2017.

That gives the company an index score of 25.5, meaning that more than a quarter of American millennials can be regarded as current customers, according to the report's definition.

This identifies a current customer "as a person who has recently purchased from the brand, ranging from 30 days to the past year depending on the category, or visited its site during the last 30 days".

And in another sign of the growing influence of the sharing economy, Uber's main rival, Lyft, recorded the third biggest year-on-year increase of six percentage points, giving it an index score of 12.3.

In addition, online hospitality service Airbnb made the list as the 12th biggest gainer (2.9 percentage points) in terms of turning millennials into regular customers.

Uber's seeming success with millennials came as a surprise to a number of industry observers, given the well-publicised series of scandals that have plagued the company, which only last month prompted the resignation of its chief executive, Travis Kalanick.

The YouGov BrandIndex findings also sit uneasily with numerous surveys that have pointed to the high importance millennials place on corporate responsibility and associated matters.

Ted Marzilli, CEO of YouGov BrandIndex, told Adweek that it appears millennials behave like everyone else when it comes to convenience and how they spend their money.

"I'm not saying millennials are not concerned about ethics," he said. "But people in the aggregate tend to make choices that are in their financial interests. So if taking Uber is more economical or convenient than waiting for a cab, I'm probably still going to call Uber."

Elsewhere, other notable brands that gained more millennial customers over the past year include social media operators, such as Instagram, Twitter and WhatsApp, although a number of "traditional" companies also made the list of fastest improvers.

These include broadcaster TLC (#5), Delta Air Lines (#8), Adidas (#10), Visa (#11), finance brands Chase (#13) and J.P. Morgan (#14), Ace Hardware (#16), Calvin Klein (#17 ) and Puma (#18).

Commenting on their inclusion, Marzilli told Adweek: "It no longer surprises me that when we do these rankings … there is often a reasonably balanced mix of new brands and traditional brands – I don't think traditional brands are all going away or will be out of business."

Data sourced from YouGov BrandIndex; additional content by WARC staff