PPC is a tough game – you have to accept it

Price elasticity (E) measures the responsiveness of the demand or supply to a change in the price of a good or service. If the price elasticity is less than one, the demand or supply is said to be inelastic. This means that Google's typical price elasticity of supply (the relative ratio of traffic increase to CPC increase) is 1. In other words, the sales profits are highest if the price elasticity of demand is 1. In PPC, the natural consequence of the law of diminishing returns is a non-linear increase in budget to scale the campaign.