Estimating Visitors and Advertising Costs of Typo Domains
Tyler Moore & Benjamin Edelman - Web Appendix to Measuring the Perpetrators and Funders of Typosquatting

It is difficult to know exactly how many people visit typosquatting domains. However, assessing the prevalence of typosquatting helps confirm the impact on consumers and advertisers. This page therefore provides estimates of the number of visitors reaching typo sites, as well as the fees advertisers pay to Google, the advertising platform we found to most frequently monetize typosquatting sites.

Our site traffic data comes from Alexa, which estimates the popularity of selected websites. For a sufficiently popular site, even the site's typosquatting misspellings receive enough traffic for Alexa to estimate their popularity. However, less popular sites receive too little traffic at their typosquatting variants for Alexa to report a rank for those typosquatting sites. We therefore begin our analysis by considering, and reporting in the table below, Alexa's estimates of the number of daily visitors browsing close typos of the 50 most popular .COM websites. On average, visitors to a site's typo domains total 0.7% of visits to the genuine site. Extrapolating with this percentage to consider all 3,264 popular sites studied in our article, we estimate that typo domains collectively receive at least 22.1 million daily visitors. If these typo domains were treated as a single website, that site would be ranked by Alexa as the 36th most popular website in the world.

The preceding analysis considered only typos of the most popular 3,264 .COM sites. Expanding to the top 100,000 sites, retaining the 0.7% estimated ratio of typosquatting site, we estimate that typo domains collectively receive at least 68.2 million daily visitors. If these typo domains were treated as a single website, that site would be ranked by Alexa as the 10th most popular website in the world. It would be more popular, in unique daily visitors, than twitter.com, myspace.com, or amazon.com!

How much do advertisers pay for this traffic? Our Table 2 reports that 57% of typo domains include Google pay-per-click ads, but prices and click-through rates vary across Google partners, and to our knowledge Google has never publicly reported its revenues from domain parking sites. To estimate Google's charges, we turn to Forbes coverage of a Trefis analyst report based on Google's recent SEC filings, concluding that Google's revenue per search is 3.5 cents. Meanwhile, Google's AdSense for Domains Case Study suggests that Google's domain parking prices are comparable to other Google prices, suggesting that it is appropriate to use Google's search prices to estimate charges on typosquatting sites. Combining these factors, and extrapolating across the top 100,000 sites with the other values estimated above, we estimate that Google's revenue from typosquatting on the top 100,000 sites is $497 million per year. In fact, comparing domain parking sites to ordinary search results, we expect that the parking sites (including typosquatting sites) have a higher click-through rate (because they typically show only ads, and no other links) and a higher conversion rate (Google's case study suggests that twice the conversion rate of search). If so, advertisers' costs for typosquatting placements could easily exceed our estimates by a factor of two or more.

We found the listed typosquatting domains using the search process detailed in Measuring the Perpetrators and Funders of Typosquatting. We built automated systems to classify the revenue sources of each typosquatting domain, as detailed in section 3. We collected this Alexa data in February 2010.