Are Offers for Paid Placements On Your Website Legit?

I have a small network of sites that get a fair amount of traffic on properties with under Page Rank 4 but it’s enough to generate interest from people claiming to want to pay for posts or paid placements.

A recent example is from Sarah working with a company called eMediaBuyers:

My name is Sarah Hill from eMediaBuyers.
I am reaching out to check if you would be interested in publishing a ‘sponsored post’ on your website [REDACTED] We get articles published on high quality publications for our clients every month in over 20 verticals. Obviously one of the categories is yours.
Please revert back with your base price & publishing terms, so we can take the discussion further.

If you have any queries,.please read our FAQ here.Thanks for your time and we look forward to working with you soon.

This is typical of emails I receive on a daily basis. It almost seems like I get more of these emails than visitors sometimes.

I’ve gone back and forth with numerous people about getting these paid placements on my websites, negotiating price and terms, and after many have agreed to the terms, I have closed exactly zero placements.

I did complete a sale for one of my sites probably 10 years ago but that was the only time and haven’t heard from those people since.

A couple years ago I had agreed to post some quality paid placement articles on my site with the promise that I would be paid after the posts were live. I got radio silence from the scammer client after the posts were live.

I have since rejected posting anything until I was paid and have yet to be paid.

Are these just Google employees fighting spam? Are they just scammers trying to get posts up for free?

Have you had a similar experience? Are there actually legitimate advertisers paying bloggers for this service?