Buttons are not stackable items. They are also not tradeable, either to other players or any kind of store.
The default action for buttons is to polish them. This is done by left-clicking and results in the message: "You rub the buttons on your clothes and they become more shiny." This changes them into polished buttons, which are used in Animal Magnetism. This requires level 3 Crafting and grants 5 Crafting experience, and is the only use for buttons.
The examine text refers to a pantomime character based on the real-life Richard Whittington. Interestingly, the shortened form of Richard ("Dick") is censored out by the chat filter in the game. This is also demonstrated by the address label, since players couldn't say "Address" before.
Buttons were made untradeable after the Trade limit was put in place due to players scamming others by saying the buttons were rare and valuable.
Strangely, polished buttons aren't members only items, while normal Buttons are. The act of polishing turns buttons into free to play items.