To make your job effective, it requires a tool. If you have none, then don't try to get serious with arbitrage betting. Although many believe that sports arbitrage is the best way to make money in sports betting, there are actually only a few who have succeeded in this, leaving the rest to be just normal bettors who rely on self-analysis and take risks on their bets.
The job is quite interesting because there's zero risk, but it's important to ask yourself if you're capable of doing it.
What kind of tool are you referring to? Are there also tools that can be used to evaluate bets on different bookies? If so, that would definitely make the work easier for those who are willing to do arbitrage betting. I also think that though it is difficult and time-consuming, anyone with dedication and a will can do it.
All it requires from a person is that they evaluate different bookies for the odds for the same matches, research whether the bookies are authentic and paying, and place their bets with whatever amount they wish to use.