Home › search ads 360 When setting a CPA, ERS, or ROAS target for a bid strategy, how much conversion history should be considered? By · Monday, December 17, 2018 When setting a CPA, ERS, or ROAS target for a bid strategy, how much conversion history should be considered? 3-4 weeks 2 weeks 3 months 1 week Correct answer is: 3-4 weeks search ads 360 GA Gaurav Arora, Digital Media Lead. 10+ years running paid media and tracking for brands in the USA, UK and Canada.