I remember when I'm still with paid to click sites before, you'll earn that $5 for likely a month. And if you want to promote, you have to put some money on it, I mean a budget for advertisement or marketing.
But for operators/owners, it is still profitable as they'll earn from the advertisers that they'll pay them to display those ads in their site.
I asked because i never tried one of this and wondering if there is something in beneficial , but as you said looks like a waste of time.
There are sites that allows you to buy referrals that isn't being referred by someone so they're free referrals and that's why the site automatically gives you those floating referrals for specific period of time depending on your budget. But that's no assurance that they'll be active.