Currently trading fee is 10 BTS for each order and 0 for cancellation. It is obviously lower than transfer fee, only 1/4 of it. However, I want to argue for lowering trading fee for several reasons.
First, we can attract more users from centralized exchanges. "Almost zero fee" can be a good catch phrase. Our most important product is the exchange platform and we need to advertise it. Luring new users with lower fees first, considering a profit then (Just curious, how many BTS are reduced from trading?)
Second, lowering trading fees can lead to much frequent orders. Unlike transfer, people are more likely to do order when the fee is low. That is, lowering trading
Third, most importantly, we need market makers. In the centralized exchanges, they place orders several thousands times a day or even more, because the exchanges do not charge for "unfilled" orders (but we do). 10 BTS per filled order is not that bad. But for every unfilled order is horrible.
Lowering trading fees can be a temporary option, like only 3 months. When we have enough user base, then we can calculate the real numbers.