Noob question: What are pins?

What are pins? I see people constantly buying-selling pins, so I want to know, thanks.

 

wow...there things to make you a member. the person basically paid for it and is now giveing you the number (code) to make your account a member for 1 month

 

Oh, thanks a lot. I thought it meant bank pins or something, lol.

 

numbers you buy that when you put into the rs site give you 1 month of membership onto your account each.

 

how exactly do you put on the pin number into your account?

 

Edit.