I think this comes in different flavours. (1) Sales Channel Flavour. This is a guarantee you use to improve conversion rates, by trying to remove any reluctanc

I think this comes in different flavours. (1) Sales Channel Flavour. This is a guarantee you use to improve conversion rates, by trying to remove any reluctance possible. This is usually where you find the "hoops" to lower the number of actual claimants. Generally, highly optimized sales "funnels" are found in segments with high margins & high advertising costs. A 5% return rate is no big deal if you spend 40% on media/advertising. (2) Heirloom Product. Say you sell a $500 camping knife. It's designed to last generations. Besides marketing, a lifetime guarantee frames the product mission in nicely concrete terms, with natural feedback mechanisms. IE, guaranteeing the product for life helps ensure you make it to last a lifetie. (3) Just-easier flavour. This is more common now, with amazon/yelp/charegbacks/etc. Money back might just be the easier way of dealing with unhappy customers. For a mature company easy=cheap. For a startup, easy means minimizing "escalations:" Chargeback disputes, Let me speak to your manager, etc. You need to watch out for no. 3. It could be in the "do things that don't scale" category.