A lot of people mention PTC sites, and various of scams that had popped up during that era. I'd also like to add, possibly one of the first experiences with cryptocurrencies, a cloud mining Ponzi, named Coinintellect, if I'm not mistaken. It supposedly a free plan, but required you to upgrade after one or two payouts.
I actually received both payments, the second one was almost lost, because they went bankrupt, so instead of BTC or PayPal payment, they paid via Dogecoin. The payout was valued a mere $5 payment, which back then, was 30.000 Doge. Stupid me sold them, I'd have a decent amount of money if I hadn't.
A very long time ago, PTC sites gave a lot of profit. When the price of Bitcoin was low, PTC sites would give satoshi and they were a means of earning for low income people. You do not have to deposit to earn on these sites.
But later some people started ponzi scheme business behind the name of PTC. They have snatched huge amount of money from foolish people in the name of revenue share. These were not actually PTCs, these were ponzi schemes.
Not quite exactly, PTC sites and faucets are paying the exact, or at least close, to what they were paying back then, but in terms of value. PTC sites would usually pay 1/10 of a cent, up to a single or two cents at maximum. In the past, those cents were the equivalent of a few hundred Satoshi, nowadays, you'd get 2-3 Satoshi at best.
For instance, Freebitco.in, probably the oldest still operational faucet, is currently paying a minimum 0.00000002 BTC per roll. A few years ago, I remember it paid a minimum of 800-1000 Satoshi per roll. Their value however was almost identical to what it is now. I was on the lucky side, since some of the BTC I had acquired through faucets was kept for quite a few years, and sold when BTC was actually worth something.