The problem is that you then have to
A) Find those businesses
B) Sell it to them
I suspect B) is the most difficult, especially for programmers who may not have a deep network into fortune 500s.
I also have a feeling that if you could sketch out a way to do B) in a blog post you may write the most valuable post ever made.
Not asking you to write a business book or anything, but can you give an example of the sort of thing you're thinking of? (Is callinwith.us an example?) I looked at Twilio because I thought it sounded really cool, but in the end I couldn't think of many Twilio applications that 1) have a clear revenue model, and 2) aren't already features of Goldmine or similar that anyone who wants it would already have.
I guess I feel that since it's SO simple and obvious it isn't worth anything. It was more of an itch I wanted to scratch, so I did.
> I guess I feel that since it's SO simple and obvious it isn't worth anything.
There are lots of "simple and obvious" things that aren't. "Hey, this mold kills bacteria." Sometimes, realizing what's simple and obvious is the valuable bit.
This is the least hard problem in startup-dom, because Twilio lets you solve Serious Problems for Serious Businesses and they are ecstatic to pay money for them. (P.S. In case it isn't obvious, don't charge based on what you're paying for Twilio. Underlying phone service: cheap. Application logic: expensive.)
There are a lot of one-week Twilio applications worth 5 or 6 figures to the right people.