Will multiple preorders give you more slots on a single account?

If you apply more than one Nightfall preorder keys to one account, will that account gain more than one character slot? I know the preorder packs were probably not designed with this in mind. I ask because I got my Factions preorder for considerably less than what they are now charging for character slots. Also, this might be a good option for people who want a few more slots, but don't have or want to use a credit card online. Most of the major retailers who sell preorders have no problems accepting cash.

I don't think it will let you attach another preorder, once you have it, you have it