It means that you lead someone astray.... in other words, when someone new registers, they can put down who referred them to the site. So you've managed to wrangle one person over to otc.
I don't have any ,but I would think its when you tell someone about OTC and when they setup their profile it asks who referred them ,of course you may have misread what it said and you actually "REEFerred" someone which is a whole other topic .