Purchased Fame: Exploring the Ecosystem of Private Blog Networks Tom Van Goethem Najmeh Miramirkhani imec-DistriNet, KU Leuven Stony Brook University
[email protected] [email protected] Wouter Joosen Nick Nikiforakis imec-DistriNet, KU Leuven Stony Brook University
[email protected] [email protected] ABSTRACT similar businesses can provide significant competitive advantages. For many, a browsing session starts by entering relevant keywords The prices for Search Ads, advertisements that are shown on top in a popular search engine. The websites that users thereafter land of the result pages and may cost more than $50 per click [32], are on are often determined by their position in the search results. indicative of the monetary incentive to score high in search results. Although little is known about the proprietary ranking algorithms There exist numerous black-hat SEO techniques that can be lever- employed by popular search engines, it is strongly suspected that aged to improve the rank of a website. For instance, by overloading the incoming links have a significant influence on the outcome. a page with related keywords, the relevance score of the search algo- This has lead to the inception of various black-hat SEO techniques rithm can be manipulated [19], or by ranking low-quality websites, that aim to deceive search engines to promote a specific website. often filled with malicious content or bloated with advertisements, In this paper, we present the first extensive study on the ecosys- for trending search-terms [16]. As a result of the continuously im- tem of a novel type of black-hat SEO, namely the trade of artificially proving detection of SEO abuse [23, 26], many of the black-hat SEO created backlinks through private blog networks (PBNs).