We have several large scale businesses that are paid customers and find it cheaper to use us, than build it in-house. It's about the cost of an engineer, and that's a fraction of what they will incur, ongoing operating costs notwithstanding
As a professional developer I would say that its not trivial, at least not cheap to develop. Theoretically all problems you know how to solve are trivial. Professionally you know that developing a solution that is flexible, reliable, supportable, extendible, user friendly and maintainable takes time, expertise and money to develop.
Providing a middleman with this kind of information is a little too much trust for me to think in terms of cents per action.
Spying-as-a-Service, haha!