What are the reported effects of a pilgrimage to Saint James of Compostela? In Catholic traditions, pilgrimages are sometimes undertaken with a view that specific effects may adhere to the pilgrim.  For St. James of Compostela, are there specific traditions about what a pilgrimage to this site in particular can expect to happen that would be different from other pilgrimages?
Though not as holy as Rome or Jerusalem, the Cathedral of Santiago, believed to be the resting place of St. James, did confer special status.

Specifically:


Pilgrims who completed the journey in a Jubilee Year were often given a plenary indulgence, forgiving them of the (earthly) consequences of a crime.


Additionally:


  
  There is still a tradition in Flanders of pardoning and releasing one prisoner every year under the condition that this prisoner walks to Santiago wearing a heavy backpack, accompanied by a guard. (from Wikipedia)