The Sponsorship Pyramid is a theoretical construct to describe the graduation of sponsorship-packages. The main sponsorship, which will be awarded only once, is on top of the pyramid. Packages that are going to be awarded more than once, but which are still very valuable (e.g. "premium sponsor") are one level below. The longer one goes down the pyramid, the wider the packages are going to be - they are going to be awared more often and offer less opportunity for differentiation for the sponsor.
A lot of times, in practice, the different levels of the sponsorship pyramid are being labeled as "Gold"-, "Silver"- and "Bronze-Partner".