Looking at the date, this isn't that surprising. The idea itself is a bit older: the Iowa Electronic Market had been taking election bets since the late '80s,

Looking at the date, this isn't that surprising. The idea itself is a bit older: the Iowa Electronic Market had been taking election bets since the late '80s, but they exploded in popularity in the mid 2000s. HP had an internal prediction market that allegedly estimated DRAM pricing very accurately. Pfizer had one where employees could "bet" on new product ideas and there were tons of startups trying to build them for movies, sports, etc. I haven't heard much about this since then, or perhaps the idea of crowdsourcing has just become pretty standard.