That’s according to a study conducted by identity management platform provider Gigya.

Of the 2,000 consumers it polled in the United States, a whopping 88% said they had logged into a website or mobile app using a social identity associated with services like Facebook, Twitter or Google+. In the United Kingdom, 66% of the consumers polled indicated that they’ve used a social login.

Both numbers represent a significant increase year-over-year. In a similar survey Gigya conducted in 2014, 77% and 60% respondents in the U.S. and U.K. respectively said they had used a social login.

On both sides of the pond, the most commonly cited reasons for social login use are all related to convenience. 56% of respondents in the U.S. and 43% in the U.K. indicated that they wanted to avoid registration forms, and 43% and 28% respectively said they didn’t want to create and remember another username and password.

Other reasons for using social login include a desire to use the same identity across devices and share content more easily.

Interestingly, social login activity is not just associated with younger users. According to Gigya, “Our survey shows that 75% of US consumers ages 55+ have used a social identity to authenticate on a website or mobile app, as well as 62% of UK consumers in the 55+ age range.”

Given the widespread and growing use of social logins by consumers, companies not employing social login might have good reason to revisit the functionality. But in doing so, they should keep in mind that for all of the advantages, including potentially higher conversions, there are challenges too.

Among them: loss of control, limited availability of data in some cases, and the need to adhere with policies that might be more restrictive or liberal than desired.

Of course, in either case, a lot depends on what happens after users log in and even where social login is used to great effect to improve user acquisition, the ability to keep users engaged is ultimately required.