I used to use
I used to use some providers that based their software on API's from third parties. Third parties that could make detrimental changes, revoke access or suddenly start charging loads of money with no warning. The problem is that I am offering those services (with some markup) to my customers and when I can't with no warning, I look bad. At the moment, there are two things I can't do for my customers and I have no idea if I will be able to in future. Maybe if I spent $1,200 and moved from Android to iPhone and also had to sign up with Apple, it would work again. Then again, maybe Apple's next update would make my iPhone unusable for the purpose. If I could charge hundreds of dollars for the service, no problem, but it's only good for an addon of $50 to my other services. (my cost is $15 and 10 minutes of time so it's not that profitable to start with).