Why are there so many "kangtao" or surewin tips for sales?

I was bewildered why would any one give away a surewin tips at such low rate where they could earn 10 of thousands with it themselves? put youself in his shoes would you??? i must admit there are opportunites in soccerbetting and i would call that an edge with a "higher chances of winning" but to call them a surewin tips is an overated statement unless you are one of the bribed key players or bribed key officials there is still a certainty of losing.