The document shows publishers' viewability waste in three sections. Section one shows inventory levels of 100M impressions at 50%, 40% and 30%. Section two calculates the 70% of impressions that are viewable, showing 57.1M, 71.4M and 42.9M viewable impressions. Section three calculates the unusable impressions as potential viewability waste, showing totals of 71.4M, 57.1M and 42.9M impressions respectively, with an overall potential viewability waste of 171M impressions.