As ITwire reported, Groupon Australia (trades as StarDeals.com.au) declared last week that just in few months after launch Stardeals.com.au web site managed to acquire more web traffic than any competing web sites (biggest competitors are reportedly Scoopon, Spreets, Cudo, JumpOnIt/LivingSocial). Representative of US based pioneer of group purchases industry refers to Hitwise traffic statistic.
However competitors, namely Cudo, doubt that this statistic reflects the reality and Hitwise data has several major flaws: limited coverage (no Telstra and Optus for example), traffic is measured at providers (not users) so it is easier to use bots and tricky ads to inflate the statistic.
In my personal opinion these doubts look reasonable.