Amazon has dealt with sales of counterfeit goods on its site for some time, and despite its efforts to thwart third-party knockoffs, some consumers remain cautious.

In a February 2018 survey conducted by Survata for CPC Strategy, nearly six in 10 US Amazon buyers who had made a purchase on the site in the past six months said they're somewhat concerned about counterfeit products on Amazon, though they haven't had a problem yet. 

Meanwhile, a smaller but still significant share of respondents (14.4%) said they were very concerned about this issue. 

And brands have not only taken notice of Amazon's counterfeit problem, but they've taken action as well. Birkenstock, for example, made headlines in 2016 when it removed its popular sandals from Amazon and ended third-party authorization needed to sell its shoes on the marketplace. 

Still, consumers continue to unwillingly purchase counterfeit goods. According to a November 2017 Vitreous World survey for MarkMonitor, 31% of internet users worldwide have unintentionally bought a knockoff online, an increase of 23% from 2016. And it hasn’t just happened once. Some 34% said they were tricked two to three times, and another 5% said they unwillingly bought a counterfeit item more than five times.

Marketplaces are the leading channel where counterfeit goods are likely to be purchased, according to the Vitreous World/MarkMonitor study. More than four in 10 respondents had unknowingly bought a fake good from an online marketplace.

In China, where a sizable portion of knockoffs are created, local online marketplaces have been proactive in reducing counterfeit goods on their platforms after being labeled by brands as complicit in the sale of fakes.

Alibaba, for one, has been aggressive in recent years to combat counterfeits on its site. Recent measures include using blockchain technology to track cross-border goods, including manufacturer information, through a partnership with logistics company Cainiao.