Sometimes lesser is better - If you are on a tight budget, bidding with a lower maximum SoV will usually result in a bigger 'bang for your buck'.

Take for example, 2 bids at the same bid amount over the same period, bid A with 100% max. SoV and bid B with 50%. Bid B will likely cost less than half of bid A, but its reach - the number of people who actually notice the ad - will not be that much less.