Adding people to your email list surreptitiously, via frustration or because of some incentive (like 10% off) is a great way of building a high number of subscr

Adding people to your email list surreptitiously, via frustration or because of some incentive (like 10% off) is a great way of building a high number of subscribers but I doubt this does anything to your bottom line. In the case of discounts for sign-up it's almost certainly negative.