It's the thing that is need to be done if you want to become a whale. I don't know how Americans do that and whether they do it at all, but I'll tell ya how we do it in Russia.

who is a plug?

Plug is a person from whom you are gonna buy, or sell, your cryptocurrency. Often we are talking here about large volumes. 15,000$+ I mean. Cause for such people usually 15k is not a big sum

pluses of having your own plug

Usually the percent that is taken for the transaction from fiat to crypto is very low. Below 10, I mean, and usually lower. It's the someone you know good at least, not some fucking people on the internet you know nothing about.

how to find your own plug

Basically, the receipt here is different for everyone. I have two people from whom I can buy cryptocurrency, STEEM included. I get to know them by personal connections. But whatever goes generally, meet your plug at some blockchain lecture or other event. But it has to be advanced. I was in some event like it, I felt like no one knew what blockchain is, lecturer included. There was only one trader, and he had volumes lower then 2k$. No sense in going to shitty lectures.

I hope this post helps, stay low key, and say how you do it in your native country.