[tomtang0514]

As an engineer in a Ads company, I totally agree. It's not just grab ad content from your customer, write some api integration with various publisher and send them the ad. The complexity involved in serving an ad properly and efficiently is way beyond the understanding of outsiders. Rotation, different kind of measurable metrics (we have at least 3x metrics than you can see from google analytics), ad serving efficiency (believe or not, we are able to serve ads faster than some publishers serve their own content), tons of targeting configurations and more. Tracking makes all those things possible.