Scaling doesn't work with a something like this for 2 very obvious reasons. Number one: we all tend to be in relatively low internet traffic businesses- so you can't just double your spend to get double the work - if it doesn't exist, you can't get it. Number two: having a very optimised account means spending double doesn't lead to doubling customers - it means lower quality traffic. If you're already getting the best traffic at the best price, why bother chasing the lower end of clicks that are more ambiguous and cost a lot more per job overall.......you need to consider your own circumstances before blindly applying marketing principles to things.