I have sold an exercise bike and expected the transaction fees of 12.8% plus regulatory fee 0.42%. However I was charged extra £45.83 as an ad fee standard. What does it mean? I cannot find it anywhere in the fees info. The value was £335 and the transaction fee is already high of £45 but I understand it is a must. However nothing is talked about an ad fee standard charge. So I am getting only £240 out of the sale. How is that possible? Would anyone know please?