The only right answer is to A/B test on your own product. It can work out that your initial conversions are higher but your paid conversions are much lower, so

The only right answer is to A/B test on your own product. It can work out that your initial conversions are higher but your paid conversions are much lower, so make sure to test the net result. Convincing people they can cancel their account and get a 100% refund can go a long way, if that makes sense for your product.