I can't speak for development work, but for consulting work this is fantastic. We completely turned my old business around using this. We went from fighting to

I can't speak for development work, but for consulting work this is fantastic. We completely turned my old business around using this. We went from fighting to sign 3k/month retainer clients to signing multiple 8k, 10k, 12k and even a 17k month retainer using this strategy. In my experience, the clients that don't like this arrangement are the ones that end up being bad clients down the road anyways. The ones that do like this, see the value in seeing an expert evaluation of the problem before spending lots of money to fix something they haven't yet identified.