in a perfect world arbitrage betting indeed has no risk since you are betting all the possible outcomes and benefiting from the different odds in different sites
BUT almost all sites are against arbitrage bettors ( except few asian ones ) which means sometimes the books may void your winning bets so you end up losing
I partially agree with you here. Sportsbooks only void bets in certain cases(Match suspended, Player retired etc) and not because you placed an arb. They generally limit or ban arbers, but allow them to withdraw their winnings(Reputable sites like Bookmaker etc).
Op is clearly advertising something which everyone know and there are softwares out there(Rebelbetting, Betburger etc) to help with this which is why what he is offering is pointless.
not really mate , books do shady stuffs a lot of the time and if you are just betting normal stakes then you can afford a voided bet unlike when you are arbitraging when sometimes you may stake your whole bankroll on a certain match
if one of your bets lost in one bookie while the other bookie voided your bet that won you will be on huge loss
it happens and you would be surprised how dirty books can be sometimes , here is an example recently when nitrogen voided a legit market ( after people raged on reddit and SBR they honored the bets tho )
https://bitcointalk.org/index.php?topic=5176799if you had an arbitrage bet and the winning part was on nitrogen you can easily bust a lot of money ( arbitrage betting is much more aggressive than normal betting so as I said sometimes people stake a large percentage of their bankroll )
also personally I had a bet on one of the Germany amateur matches , I divided my stake on fortunejack and sportsbet
same bet in both sites but sportsbet paid me my winnings while fortunejack voided the bet , the match was paused for a little of time then teams continued playing and the bet won
so even when betting same match and same outcome each bookie will act differently if something happened during the match