This article proposes a new model of customer behavior with churn: the gamma/Gompertz/Negative Binomial Distribution (G/G/NBD). Tested on six markets, the model leads to a superior (i.e., four markets) or similar (i.e., two markets) fit to the data compared to the Pareto/NBD. A MATLAB code, a note and a spreadsheet are available at http://bit.ly/niABgB. The note is also shown at http://dl.dropbox.com/u/7097708/gg_nbd_MATLAB.pdf. Link to the article
BEMMAOR, A.C. and GLADY, N. (2012). Modeling Purchasing Behavior with Sudden "Death": A Flexible Customer Lifetime Model. Management Science, 58(5), pp. 1012-1021.