"Do not wait for leads to become paid users to decide on the quality of paid ads campaigns: focus on quick metrics and tailor experiments to one step of your fu

"Do not wait for leads to become paid users to decide on the quality of paid ads campaigns: focus on quick metrics and tailor experiments to one step of your funnel at a time." This sounds very familiar... in fact it sounds a lot like "Respond to change instead of following a rigid plan" from the agile manifesto.