Since Ashley Madison was hacked and details of those using the cheating service were posted online, the company that owns the site claims its membership numbers have actually increased. However, figures published Monday show that traffic to the website has plummeted by more than 80 percent while there has also been a significant shift in the location of its users, with Vietnam replacing the U.S. as the country with the most visitors.

Last month Avid Life Media (ALM), the Canadian company that owns Ashley Madison as well as similar websites like Established Men and  Cougar Life claimed membership of its cheating service had increased from 39 million in August — when hackers breached its security and published account holders' information online — to 43.4 million. Some questioned the validity of those figures based on ALM's previous practice of creating fake accounts to lure users to try the site.

Figures provided by SimilarWeb, a marketing intelligence firm, indicate that Ashley Madison was receiving 171 million visits in June, two months before the attack, but this figure had plummeted to 30.9 million by December.  The company says that most of its traffic comes from "racy banner ads" (44 percent) and referral traffic from ads placed on porn sites, file-sharing websites and pop-up ad networks.

Ashley Madison web traffic plummets Ashley Madison has seen traffic to its website, which promotes infidelity, drop from 171 million in June to just 31 million in December. Photo: SimilarWeb

"The data shows that Ashley Madison's global Web traffic plummeted 82 percent since its hack was announced this summer," Joel Zand, digital insights manager at SimilarWeb, said in an email. "The marital infidelity site has also seen a major shift in its global user base, losing considerable North American traffic from the U.S. and Canada, with increased traffic shares from countries in South America and Asia."

Prior to the hack, the U.S. accounted for more than 28 percent of all traffic to the website and was easily the biggest country by users, but today that has dropped to 4.6 percent with the huge media attention and negative connotations clearly affecting the website's ability to attract customers in the U.S.

Ashley Madison traffic by country While the U.S. has dropped from first to sixth, China is now the biggest referrer of traffic to Ashley Madison Photo: SimilarWeb

Conversely, Vietnam, which was not among the top 10 referrer countries in June, is now number one, accounts for 18.2 percent of all  Ashley Madison traffic. It is unclear why Vietnam is suddenly a huge referrer for the cheating service.

Ashley Madison has not responded to a request for comment at the time of publication.