1500 visits per day is not 'popular' by any stretch of the imagination, not to rain on your parade but that's still very small fry.

What you do have is validation that you have something going on there, now you need to analyze what that something is and if there is a way to get it to grow to a substantial multiple of what you have today.

So, what I would do with it is analyze the crap out of it to see if it has (autonomous) potential for further growth.

You also need to figure out why it dropped again.