Why do Jehovah's Witnesses travel in pairs? Why do Jehovah's Witnesses travel in pairs instead of a group and go proselytizing door-to-door? What is the typical arrangement (friend and friend, sister and sister, brother and brother, husband and wife, etc.)? Are these people paid by the Watchtower to minister?
Mark 6:7 (NWT)
  Now he summoned the twelve, and he initiated sending them out two by two, and he began to give them authority over the unclean spirits. 
  
  Luke 10:1 (NWT)
  After these things the Lord designated seventy others and sent them forth by twos in advance of him into every city and place to which he himself was going to come. 


Jesus did this 


so we would have someone to work with, and 
for consideration for the householder, so a large group of people don't show up at their door among other reasons.