如果曝光率是广告系列的首要目标，那么广告客户应当选择哪种出价策略才是最有效的？

Target Impression Share is the most effective bidding strategy when impression share is the primary campaign goal. This strategy automatically sets bids to help achieve a target percentage of impressions at the top of the page, or anywhere on the page, for a specific location. Enhanced Cost Per Click (eCPC) aims to maximize conversions by adjusting manual bids, not impressions. Maximize Clicks focuses on getting as many clicks as possible within a budget, which doesn't directly prioritize impression share. Maximize Conversions is designed to get the most conversions for your budget, not to increase impression visibility.