Google: "become trusted sythe"
Be on Sythe for a long time and they will eventually use you, but nobody is gonna use you within next month unless they are drunk.
Also you might want to refrain from spamming your offers to middleman trades if people are just interested in buying/selling things. You can create a thread in the Middleman section and bump that one once in 8 hours. Otherwise don't offer your service. People come to you if they want to, you don't go to them.
You should request to lock this as it's the wrong section, once done post in the middleman section or at least try to branch yourself out first before trying it