Ad Metrics Dashboard: Requirements and Numbers

An ad network that shows 864 million ads a day shows 864,000,000 / 86,400 = 10,000 ads per second on average. If 0.6 percent of those ads are clicked, the same day holds 5,184,000 clicks, or 60 clicks per second. Each click can cost an advertiser money, and each ad also appears on a chart that the advertiser watches during the day.

Those two uses need different numbers. The chart needs counts within minutes and accepts a small error. The bill needs counts that are exact, final, and still explainable months later