It could also relate to a popular singer where he keeps recording top hits. The hits just keep on coming.

Hi, sometimes it refers to a series of misfortunes.

Exactly! It could mean many things positive or negative. What it means precisely and how you can understand it ,requires a context. So maybe you can add some details. :)

It was used originally by radio announcers to say that their radio station was going to play one popular (hit) record after another. Generally, if it is used in a well-meaning way, it means one good thing after another is happening. However, it is often meant in a sarcastic manner to say that one negative thing after another is happening. "I had a flat tire yesterday, then had an accident with the car. Today I find out that I have replace the motor! The hits just keep on coming!"