Some implementations of paywalls proved unsuccessful, and have been removed.[1] Experts who are skeptical of the paywall model include Arianna Huffington, who declared "the paywall is history" in a 2009 article in The Guardian.[17] In 2010, Wikipedia co-founder Jimmy Wales reportedly called The Times's paywall "a foolish experiment."[18] One major concern was that, with content so widely available, potential subscribers would turn to free sources for their news.[19] The adverse effects of earlier implementations included decline in traffic[20] and poor search engine optimization.[16]