he/she doesn't have to bet anything but if you win using his/her tips you have to split the profit with him/her but if
you lose the bet using his/her tips it will only be you who is losing and the OP doesn't lose anything.
well nothing funny in wasting other people's time , it is clear that none would ever trust such a tipster without a history or reputation
and the 50% 50 % is the good old trick where you get several people on board and give to one half home side wins, to the other side guest half wins
I knew people who managed to fool hundreds of gullible bettors this way and for quite some time