Do not forget to always check your preset material if someone exported it to you, sometimes the person will make it "preset_#mat" which may mess up your preset to not show up in the CD (Creative Den). Also, they can sometimes mistake an exported picture file, making it a JPG, but not changing it in the Material file, stuff like that. If you're worried about/want people to see your preset, they'd have to download it. And you do that by what "Birdie" said. Much luck~