A.T. Robertson Commentary Mark 1:45

"But he went out, and began to publish it much, and to spread abroad the matter, insomuch that Jesus could no more openly enter into a city, but was without in desert places: and they came to him from every quarter." — Mark 1:45 (ASV)

Began to publish it much (ηρξατο κηρυσσειν πολλα). Luke 5:15 puts it, "so much the more" (μαλλον). One of the best ways to spread a thing is to tell people not to tell. It was certainly so in this case. Soon Jesus had to avoid cities and betake himself to desert places to avoid the crowds and even then people kept coming to Jesus (ηρχοντο, imperfect tense). Some preachers are not so disturbed by the onrush of crowds.