Vivinavi

What is an MLM ？ Has anyone received a letter like this ？?

I was looking for a cream for dry skin and received the following letter, but I didn't know which product it was so I looked it up
Is it multi ？ Have you ever received a letter ？ I would appreciate it if you know
Here is the content of the letter I received. It was kind of scary, so I had to go through it.
"This is an MLM product.
It is a membership, so you need a referral to purchase it.
If it's okay with me, I can be your referral, but I think it would be better for you to listen to the explanation first and then consider it, so if you want, we can talk once via zoom or LINE call ？"