Typically you won’t have real people harvesting emails for sale - it’s much easier to get addresses in bulk by hacking services and dumping their databases - and you get password hashes as well, which makes it a much better value proposition for the time it takes.

Off the top of my head, a couple of things that it could be:

• Simple stolen card fraud - buy something small with a stolen credit card to prove it works before using it for a higher value purchase. Something where you don’t need to worry about a physical product getting delivered somewhere would be great for this
• Escrow fee fraud - commission something small, then use that as a hook to promise a much larger commission, except that they want to use some off-site service to “reduce the fees”, then “oops the money has been flagged as maybe fraudulent and you need to pay a fee to get it released”
• Money mule recruitment - again, small commission (using a stolen card) to establish a relationship, then come to you with a great job opportunity where they will send you some money via western union or something, and all you need to do is send it on to someone else, and you get to keep a cut. The catch is you are actually handing stolen funds or helping someone evade international sanctions, and you end up in prison

Here, let me pay you $700 for this item that’s worth $500 and you can just send me the extra $200 difference. I have to do it this way because it’s your father’s, brother’s, nephew’s, cousin’s, former roommate’s will and I’m just signing the whole check off to you.

Meanwhile the original check is fake and now you’ve lost the original item AND $200 and the bank is investigating you, and not them.

The “RandomUnremarkableName + Number” username format is a clear indicator of the type of person that has very low morals and is quite possibly a scammer or worse. Stay clear of those at any cost.

Unless you want to do crime or hook up. (DM me).

In the 2000s I worked in IT and we hosted a spam filter. Back then people would send out seemingly harmless email, about Jack’s golf game or the picnic on Sunday, and their goal was to build up their domain’s reputation as a legitimate sender. Then one day they’ll send out spam and it’ll get through the filter until the spam filter catches on and cuts off that domain.

It’s just bots bypassing bot filter. Most platforms now restrict activity of new user accounts to combat spam, so bot farms create new accounts, create some spam posts, wait two-three months until these accounts become unrestricted, then post some political ads en masse.