Ebbos in Santeria – Sacrifices and Offerings [View all]

Ebbos (or Ebos) are a central part of Santeria practice. Humans and orishas both need an energy force known as ashe in order to succeed; orishas, in fact, need it in order to survive. So if one would like to be favored by the orishas, or even just pay respect to these beings that are intimately involved with forces in the physical world, one must offer ashe. All things have some quantity of ashe, but nothing is more potent than blood. Sacrifice is a method of delivering that ashe to the orishas so they, in turn, can use ashe for the petitioner's benefit.

http://altreligion.about.com/od/ritualsandpractices/p/Ebbos.htm