Caitanya Mahaprabhu was most appreciative of a maidservant who brought many pots of Ganga water into a temple. He could see that she did not want recognition for her service. She only wanted to please, to serve. This, according great acaryas, is pure devotion, devotional service that wants no return, that seeks no reward, that only wants to please the Lord and His servants -- in a word: selflessness.