If visibility is the primary campaign goal, which bidding strategy would be the most effective for an advertiser to use?

Target impression share is the most effective bidding strategy when visibility is the primary goal because it automatically sets bids with the specific objective of showing your ad on a certain percentage of eligible auctions. Unlike strategies focused on volume (Maximize clicks) or performance (Maximize conversions), Target impression share allows an advertiser to prioritize brand presence by choosing exactly where they want their ads to appear—such as at the absolute top of the page, the top of the page, or anywhere on the page. This ensures that the brand remains highly visible to its target audience, maximizing "share of voice" and ensuring the message is seen as frequently as possible within the chosen placement parameters.