Part of the issue is you don't want 100 features but only one person uses one feature, like word or Excel. If you do have a lot of features that are rarely use

Part of the issue is you don't want 100 features but only one person uses one feature, like word or Excel. If you do have a lot of features that are rarely used, you should hide as many as possibly behind an 'Advanced' area. If the feature is useful to a large set of your users, then I would agree and add the feature. If it is only 1 user asking for it, then I would not add it. I tend to be like you and think, its only 1 line of code to make it work like they want, they are a paying customer, why not make them happy. But I've been burned by this. I had a customer who really wanted a few modifications. I made 1 that would help everyone using the service. I was going to start the second one against my better judgement, but right before I did, the person using the software quit her job (where she was using it), and her replacement didn't want to use it.