Matched betting is making money from those offers the bookies use to lure people in (i.e. Bet £10 and we'll give you another £20 bet for free). You have to place a bet on an outcome (with a bookmaker) then bet against the same outcome (with a betting exchange) at the same odds. So basically, you win as much as you lose and then cash out the free money. So you only make £20 in the example above. It's a very time consuming process and an absolute bugger if something goes wrong (you can lose money doing this if you don't know what you are doing or make a little mistake). I tried it once, couldn't get my lay bet on in time but ended up winning anyway so I cashed out and haven't touched it since.
I think the people who are really successful at matched betting are the ones who spend a great deal of time at it (like anything else) and although it is touted by a lot of people as a great side hustle, there's still always the chance of something going wrong and you ending up losing money. You can also get banned by the bookies because, for some reason, they don't like matched betting
Also, I was self employed until January of this year, both working as a contractor and running a small business, and there's been some hilarious stuff Emma's done in the guise of being self employed, like treating her home broadband as a business expense when she was working from home

