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Old tails: a crude power law fit on ebook sales

We use R to take a very brief look at the distribution of e-book sales on Amazon.com. Continue reading Old tails: a crude power law fit on ebook sales

Posted on Categories Applications, Expository Writing, Pragmatic Data Science, Pragmatic Machine Learning, Statistics, Statistics To English TranslationTags , , , , , ,

Living in A Lognormal World

Recently, we had a client come to us with (among other things) the following question:
Who is more valuable, Customer Type A, or Customer Type B?

This client already tracked the net profit and loss generated by every customer who used his services, and had begun to analyze his customers by group. He was especially interested in Customer Type A; his gut instinct told him that Type A customers were quite profitable compared to the others (Type B) and he wanted to back up this feeling with numbers.

He found that, on average, Type A customers generate about $92 profit per month, and Type B customers average about $115 per month (The data and figures that we are using in this discussion aren’t actual client data, of course, but a notional example). He also found that while Type A customers make up about 4% of the customer base, they generate less than 4% of the net profit per month. So Type A customers actually seem to be less profitable than Type B customers. Apparently, our client was mistaken.

Or was he? Continue reading Living in A Lognormal World