Lord Sri Chitanya, as Krishna-Madhava Himself, has explained the features of Krishna's names. He cleared that Krishna's first eternal expansion, Sankarshan (Balaram) was also known as madhav because he loved to eat sweet honey, madhu. Lord vishnu, the personality expansion of Krishna, is also known to be madhav due to possessing one of the six complete opulences, Vaibhava Laxmi, also known as Madhavi (she gets this name because of attraction/affinity for Madhava/Krishna) Ref: Chaitanya Charitamrita, Madhya-lila.