- "An area that currently has its spawn improved is not be eligible for donations or random selection. Thus, an area cannot have its spawn increased two days in a row."
Source: Cyclopedia Map
From Tibia forum, posted by Burchan:
"> If an area wins the bid, is it excluded from the pool
> of randomly selected areas or can it still receive
> another respawn boost if it's selected randomly?
Your first assumption is correct."
Source: Tibia Forum
"> I'd say it should be always random. The way you
> propose will help only players with highest levels.
> Always faster respawn at Roshamuul and Library.
Since those two hunting grounds are in different areas, it is highly unlikely that the bonus will always apply to them (especially since only one area can be "chosen" by the inhabitants of a game world). Also keep in mind, the donations of other areas remain and are not reset as long as the respawn area bonus is not applied to them. Therefore, trying to get the respawn bonus on the same area every two days will become quite expensive."
Source : Tibia Forum