Target impression share is a Smart Bidding Strategy that automatically sets bids with the goal of showing your ad on the absolute top of the page, on the top of the page, or anywhere on the page of SERPs.
Target impression share is available either as a standard strategy in a single campaign or as a portfolio strategy across multiple campaigns.
Impression Share only includes the Google Search Network.
When to use Target Impression Bidding Strategy?
User Target Impression share to increase brand awareness.
For some situations, ideal performance means being present on certain search terms.