My matched betting results using the no-lay method - around $15K profit in 3 months
Results in attached graph.
These are my personal results from a couple of years ago. I'm about to start back up again, as I was stopped in my tracks by kids (you need to commit a few hours on a Saturday afternoon for this to work).
In basic terms, matched betting is taking advantage of the promos offered by bookmakers. The obvious ones are the deposit bonuses, but the really profitable ones are the offers made on horse races, where you get a bonus bet if your horse runs second. Sportsbet for example offers these on the main race meetings every Saturday and most Wednesdays.
In short, you place a bet with a negative expected value (say a $3 horse tip), knowing that if it runs second or third you will get a bonus bet, that you can turn into cash at 70-80% of the bonus value. You "lay" your bets using Betfair to limit the downside of the initial losing bets, and to lock in profit on the bonus bets you receive. The software that I use (Bonusbank), calculates all of the expected values, and tells you what bets to place. As the value of each bet can be determined by a formula, the only risk is human error (such as placing a bet on the wrong horse). Just to note with my graph, I use a more aggressive method called no-lay, which has a slightly higher return but does come with an element of risk. I'd recommend everyone starts with the full-lay method (most people use it for their entire matched betting career), which would return a slightly lower profit but a much smoother graph than mine.
You'll need around $500 to get started, but you can build your bankroll very quickly. My affiliate link is below if you're interested, they've got a free tier where you can learn the basics of the system, and cash in on some deposit offers.
https://bonusbank.com.au/?aff=Xylene
Obviously the biggest thing to watch out for here is staying disciplined. Your profits are sitting with a bookie until you withdraw them, and for a lot of people there's a temptation to just punt it away.
Happy to answer any questions!!!