Archive for the ‘Interactive marketing’ Category

11
Jun
By Mayank Bawa in Analytics, Blogroll, Business analytics, Interactive marketing on June 11, 2008
   

I had the opportunity to work closely with Anand Rajaraman while at Stanford University and now at our company. Anand teaches the Data Mining class at Stanford as well, and recently he did a very instructive post on the observation that efficient algorithms on more data usually beat complex algorithms on small data. He followed it up with an elaboration post. Google also seems to believe in a similar philosophy.

I want to build upon that observation here. If you haven’t read the posts, do read them first. It is well-worth the time!

I propose that there are 2 forces in action that help simple algorithms on big data beat complex algorithms on small data:

  1. The freedom of big data allows us to bring in related datasets that provide contextual richness.
  2. Simple algorithms allow us to identify small nuances by leveraging contextual richness in the data.

Let me expand my proposal using Internet Advertising Networks as an example.

Advertising networks essentially make a guess about a user’s intent and present an advertisement (creative) to the consumer. If the user is indeed interested, the user clicks through the creative to learn more.

Advertising networks are used today on a CPC model (Cost-Per-Click). There are stronger variants of CPL (Cost-Per-Lead) or CPA (Cost-Per-Acquisition) but these variants are as applicable to the discussion as the simpler CPC model. There is a simpler variant of CPM (Cost-Per-Impression) but an advertiser ends up effectively computing CPC by keeping track of click-through rates for money spent via the CPM model. The CPC model dictates that Advertising Networks do not make money unless the user clicks on a creative.

Today, the best advertising networks have a click through rate of less than 1%. In other words, advertising networks correctly interpret a user’s intentions 1% of the time, 99% of the time they are ineffective!I find this statistic immensely liberating. Here is a statistic that shows that even if we are correct 1% of the time, the rewards are significant. ☺Why is the click-through rate so low? I think it is because human behavior is difficult to predict. Even sophisticated algorithms (that are computationally practical only on small datasets) do a bad job of predicting human behavior.It is much more powerful to think of efficient algorithms that execute across larger, diverse datasets to exploit the richness inherent in the context to enable a higher click-through rate.I’ve observed people in the field sample behavioral data to reduce their operating dataset. I submit that a sample of 1% will lose the nuances and the context that can cause an uplift and growth in revenue.For example, a Content Media site may have 2% of their users who come in to read Sports stay on to read Finance articles. A sampling of 1% is certain to reduce this 2% population trait to a statistically insignificant portion in the sample. Should we or should we not derive this insight to identify and engage the 2% by serving them better content?Similarly, an Internet Retailer may have 2% of their users who come in to buy flat-panel TV have also bought video games recently. Should we or should we not act on this insight to identify and engage the 2% by offering them better deals on games? Given that games are a high-margin product, the net effect on revenue via cross-sell could be higher than 2% in dollars.We often want to develop an algorithm that is provably correct under all circumstances. In a bid to satisfy this urge, we restrict our datasets to find a statistically significant model that is a good predictor. I associate that with a purist way of algorithm development that was drilled into us at school.Anand’s observation is a call for practitioners to think simple, use context and come up with rules that segment and win locally. It will be faster to develop, test and win on simple heuristics than waiting for a perfect “Aha!” that explains all things human.