An idea (maybe too obvious) that comes to mind would be to host people's tests and send alerts when tests fail, then work up a deal with Heroku to offer your we

An idea (maybe too obvious) that comes to mind would be to host people's tests and send alerts when tests fail, then work up a deal with Heroku to offer your web testing service as a plugin. Many of the plugin services have the same type of tiered business model. You could do something like a 30 day trial (or, alternatively, 1 test per day free), then offer services for 50 requests, 500, 1000, etc. I'm not incredibly familiar with how frequently web tests run and how many pages/forms/fields the average project has, so obviously you'd have to tweak those numbers based on what you think will generate the most revenue.