Convoys is a simple library that fits a few statistical model useful for modeling time-lagged conversion rates.
Estimating eventual conversion rates for recent cohorts is a critically important problem for anyone that works at a startup. You can't wait 12 months to see if your acquisition efforts are effective—you need to have some mechanism of judging them within 7 or 14 or 30 days (maybe less!). I had always used the Kaplan-Meier estimator to handle this: it's a simple, easily-explainable measure to estimate unobserved data. Turns out there is a better way.
It turns out we can model conversions by essentially thinking of conversions as a logistic regression model multiplied by a distribution over time which is usually a Weibull distribution or something similar. Convoys implements a few of these models with some utility functions for data conversion and plotting.
Highly recommended. I haven't had the opportunity to play with it yet but plan to on an upcoming project.Read more...