You will only see parody, comedy, quote or fact accounts asking this. This means that you exchange followers with an account around the same size as yours. You find this out by DMing the person. You say "wwyba?" and they'll reply with the number of followers they'll be at with the arranged amount of Twitter followers exchanged. You can do low goals such as 20x on small accounts, ranging to up to 1000x for big accounts. Hope this helps!
What people on Twitter mean by that is that you should send them a message that is direct which the DM(direct message) stands for. You should send them a message that looks something like @Leila, hey girl.