A clever crook will not invest in a 3 000 m² renting and hire new employees that will only reduce his income as a swindler when the scam goes perfectly...
A Short-Con is taking the money and running, a Long-Con uses something like this as a 'Convincer' to get even more money later down the line. eg
Mafia used to take over business and place small orders with suppliers, pay the bill and then make massive orders for 50x the amount (or as much as they could get away with on credit) and then run off with it without paying. The earlier payments of the bill 'convinced' the supplier that the business was genuine.
Ponzi schemes use new money to pay out older investors so new people are 'convinced' that returns are genuine and they just have to wait for it to arrive or put more money in to 'release' it or 'unlock' it (if fees are used as the reason why not paid out yet).
Pyramid schemes most of the money flows to the top with small pay-outs to all the levels to 'convince' people that money can be made if they just invest more and climb the pyramid (they cant ofc they can only 'scam' new people to get them under them and dont even realise they are scamming other people, they are 'conviinced' its genuine as can see what the top level earns)
Shills or teams operate together - best example is 'Follow The Lady' card games where the shill wins, 'convincing' people that the game is genuine. Sometimes they will pay out small bets and wait for the big bet and then the player loses it all.
Romance scammers abuse emotions of victims to 'convince' them they are real and in love to extort even more money. Always starts with a little 'loan' or 'investment' and then the amount just gets bigger and bigger until they have it all and move on to the next victim - but these victims dont attract new victims on the scammers behalf.
Its hard to get $10 out of a stranger, but once you have their $10 they will often pay thousands to get that $10 back and even take out loans or drag friends and family into it out of desperation to get their money back. Very similar to people with gambling problems.
Not saying it is anything like this ofc but a smart crook will go for the max returns using previous returns / payouts to convince new victims to put even more money into it or 'invest' to explain why the money isnt available right now to buy time for more victims to join the scheme. These people are the Ponzis, the Madoffs, Enron which go on for years or even decades before it all falls apart or is discovered. The fallacy believed here is usually that it is 'too big to fail' (the stock market crashes every 20 years or so and nothing is bigger than that).