noun. One who makes a show of liking another person with profuse or excessive displays of camaraderie, such as vigorous hand clasping, back-slapping, hearty words of greeting, etc.

noun. someone who demonstrates enthusiastic or excessive cordiality

"Another industry backslapper with music content that would not even grace an elevator. yet another plot to keep our airwaves free of rock and roll."

enthusiast  partisan  partizan  

adulator  apple-polisher  ass-licker  backscratcher  blarneyer