WebReference Interview:

"[Q]How does it rank as a chess player? [A] [...] I know the game is not really very good. It fools people into simultaneously underestimating it (because it's just a web page) and overestimating it, attributing plans and conceptual ability where none exist. Its speed is another trap. By not taking long over any move, it encourages people to also move fast. While the computer can't possibly miss the best move according to its limited view, people make huge oversights when they're playing quickly - especially people who don't often play chess and just happened across it."