UK-based analyst Juniper Research released a new study Tuesday that showed the number of "contactless" Apple Pay users nearly doubling year over year, with the total number of Apple Pay users reaching 86 million by the end of 2017.

Android Pay (Google) and Samsung Pay are also seeing big increases in usage. Still, Juniper expects Apple to dominate the contactless payment market over the next four years.

Juniper estimates that the number of people using these mobile payment systems, including Apple Pay, Samsung Pay and Android Pay, will exceed 100 million for the first time during the first half of 2017 and will surpass 150 million by the end of this year. According to the study, the combined market share of Apple, Samsung and Google (via Android Pay) increased from 20 percent in 2015 to 41 percent in 2016, as a proportion of total mobile contactless payment users.

The forecast sees that rising to 56 percent by 2021, "as the trio's combined user base exceeds 500 million," with PayPal expected "to rapidly deploy a portfolio of contactless payment and loyalty solutions that will allow it to compete effectively for market share." You can read the full press release here.

Apple didn't immediately respond to a request for comment.