As name says. Certificates are tradable. Seals aren't. It would be better if we could just trade them. Why? Because horse medals are at the moment too easy to get and they're cheap as hell. If you would allow us to trade seals we could for example load a lot of horse medals into the seal increasing the value of that seal ( and its time ). You need horse medals for that and believe me or not many players don't know that you can actually drop a horse medal down on the seal to increase its duration. It would also let us sell unwanted mounts. For example when I want a mount with % vs mob and I get 10 with def before that I have to sell them for 0 gold to vendor because I can't use all of them at once so basically certificates are wasted this way. Other benefit of that is the fact players can pick a seal they want in particular for more gold instead of getting X amount of certificates.
My raid design: THE NEXUS