Well, I believe I can answer this because I have done so much research on this topic. Linkage offers an option for you to skip the lag year of postbac and enter one of the medical schools that the postbac program offers linkage to. However, beware that at most schools you do not "automatically" get accepted by the school. You still have to have certain MCAT scores and maintain a certain GPA for the postbac. Plus, you still have to interview many times. There are only a few schools where you automatically get accepted assuming you did well in the postbac program and most of them are only reserved for underrepresented minorities and/or disadvantaged students.