According to data-crunching from Brad Alvarez of SeekingAlpha.com, 47.1% of new subscribers SiriusXM acquired through promotions last quarter, continued to pay for service after their promo term ended.That’s a moderately high stick rate for paid content subscriptions. The most surprising data in Brad’s report was that SiriusXM has a typical monthly churn rate of just 1.2-2%.That’s insanely low churn.In fact, we’re not sure how that’s possible unless 100% of “involuntary churn” is backed out of the numbers. (Involuntary churn are credit cards and debit cards that go bad for a wide variety of reasons ranging from credit limits to fraud.) We’d caution anyone Modeling these churn numbers that they are not normal….