Puzzle #40343: When is it good to gambit?

So in puzzle #40343, the solution involves trading a rook for a bishop and the opportunity to chase the king out into the open. (Sorry - I'm sure there's a way to load the whole puzzle into the post, but I don't know how.) The analysis engine says that white has mate in 11 at the beginning of the puzzle. I say that this is rated for ELO 1000 and none of us are going see that. What we *will* see is that the solution is something of a gambit that trades down material to chase the king into a more vulnerable position.

It works here, but this strikes me as a dubious thing to do in general. I've lost plenty of games in the past because I got reckless and traded material for an aggressive position. I feel like part of the reason that my skills have improved is because I take these sorts of gambles less often.

So when is it a good idea to do a gambit? Are there general principles demonstrated in this puzzle which I might be missing? I know that chasing the king to the center of the board is a good thing, but how much material should you be willing to lose for that purpose? In this puzzle, we're talking about a two point exchange. I've also seen bishop sacks (such as the Greek Gift) which pay off big. What are the guidelines for a trade like this?