On our Google Shopping campaigns, we try to target 60% overall impression share and 30% click share on our high priority/high profitability products.
Depending on the competitiveness of the market and pricing this will change. We sell products between £200-£500 which generally have between 10-20 other businesses selling the same products. We are able to achieve 60% impression share and 30% click share by managing our bids diligently and ensuring we have excluded any products which we are not priced competitively for or are out of stock.