I missed an important birthday last month; the banner ad turned 40. We're certainly not going to see the 40% CTR that this ATT ad achieved back then. In fact we're not likely to see much above a single digit or even decimal place.
At the time I don't think anyone had an idea what the click thru rate would be, but in today's data-driven world we should have some clues. We have all kinds of systems and analytic tools that predict what a CTR might be. But each of those come with one or more constraints that we often forget to convey.
- Time, data and resources will narrow the options we can use to analyze a problem; need an answer today? or next week?
- Explanations always rest on assumptions as we reduce the problem to one that is manageable; did we remember to tell anyone?
- Our mental models are biased to begin with, and we may not realize it.
- Data is left behind due to data collection procedures or application code; design choices made before we started the analysis limit what we can and can not do/say.
- Our use of data may be different than how it was intended; this is a common question when creating mashups particularly with public data.
So, say out loud "this is what we don't know"....