The best option is to hire a statistician with experience in DATA modeling and forecasting. In case she/he does not have programming experience, hook them up with a TECHNICAL person who has modest technical skills.

TWO other quick things…

Churn is a term most closely associated with customers you have acquired (and then failed to retain) and not so much to "fly by night" Visitors on your site. The latter, except in rare cases, is hard to do predictive analytics on unless you are a stagnant business.

If you want to do churn analysis, as defined above, then you don't want GA as much as you want your back-end ERP / "Orders" DATABASE that has your customer history, and just a couple of acquisition signals (campaign and source come to mind). You can and should do that now (along with customer LIFETIME value type valuable computations).

The best option is to hire a statistician with experience in data modeling and forecasting. In case she/he does not have programming experience, hook them up with a technical person who has modest technical skills.

Two other quick things…

Churn is a term most closely associated with customers you have acquired (and then failed to retain) and not so much to "fly by night" Visitors on your site. The latter, except in rare cases, is hard to do predictive analytics on unless you are a stagnant business.

If you want to do churn analysis, as defined above, then you don't want GA as much as you want your back-end ERP / "Orders" database that has your customer history, and just a couple of acquisition signals (campaign and source come to mind). You can and should do that now (along with customer lifetime value type valuable computations).