Revenue impact of blocking ads
Blocking ads may have a negative revenue impact because blocked ads won't compete in the auction on your site, and therefore won't drive up potential earnings for that ad space. Also, advertisers whose ads you block may choose not to target your site again in the future.
Choosing the "hold ads" setting may also decrease your revenue, because ads that are awaiting review won't participate in the auction either. Please consider the potential revenue impact before choosing to hold ads rather than running them immediately.