The most significant difference between mentors and advocates is the level of active involvement in the career of the protoge. Sponsors and advocates are in a position of influence in the organziation. Sponsor/advocates are also close enough to the protoges career trajectory AND personal goals to clearly see in detail where the protoge should be focusing their efforts in the near future to accomplish THEIR professional (and sometimes life) goals. In addition the sponsor/advocate is in position to be able to influence the opportunities the protoge has access to and is willing to actively "advocate" or "sponsor" this individual by placing personal reputation and political capital on the line in support of the protoge. Lets face it, if we recommend someone for an assigment, promotion, raise, committee, opportunity of any kind- we put a portion of our reputation on the line. This is the primary difference between mentors and sponsor/advocates. Many people have mentors who in fact have been playing the sponsor/advocate role -many times without the knowledge of the protoge. Until we are insiders of the leadership team we often are unaware of how prevalent the sponsor/advocacy system is.
The sponsor/advocate also plays the role of education, awareness raising and skill building which may be common to mentor relationships. One of the most challenging things about career progression is understanding exactly what you should be doing when , how to procure these assignments for yourself and how to ensure the right people know you are doing the right things. These steps cannot be accomplished independently in most organizations. Hence the need for sponsor/advocates.