InlineStyle services will keep growing consistently over the course of time as our infrastructure and support for those services grows.
Running a service requires not just the effort of setting up the service itself, but also the work we do to improve the user experience like adding new convenient features to the services that we consider important to make them well perceived to end users (think of the "For You" section on InlineStyle Tube, or the auto-federation and discovery of free music libraries on InlineStyle Music), and also by ensuring the service copes well with our single sign-on and doesn't require users to create a tons of different accounts for each service they use.
We are also committed to making sure that every new service we release becomes immediately available to existing backers without any additional cost.