如果主要廣告活動目標是提高曝光度，哪種出價策略對廣告主來說最有效？

Target Impression Share is the most effective bidding strategy for advertisers whose primary campaign goal is to increase visibility. This strategy automatically adjusts bids to help your ads appear at the top of the page, in the absolute top position, or anywhere on the search results page, depending on your chosen placement and target impression share percentage. eCPC (Enhanced Cost Per Click) is designed to maximize clicks, not necessarily impressions. Maximize Clicks aims to get as many clicks as possible within your budget. Maximize Conversions focuses on driving conversions, which is a different goal than visibility. While these strategies can indirectly lead to more impressions, they are not optimized for the specific goal of increasing exposure as directly as Target Impression Share.