Should a service layer return view models for an MVC application?

Question

Say you have an ASP.NET MVC project and are using a service layer, such as in this contact manager tutorial on the asp.net site: http://www.asp.net/mvc/tutorials/iteration-

Answer 1

Generally, no.

View models are intended to provide information to and from views and should be specific to the application, as opposed to the general domain. Controllers should orchestrate interaction with repositories, services (I am making some assumptions of the definition of service here), etc and handle building and validating view models, and also contain the logic of determining views to render.

By leaking view models into a "service" layer, you are blurring your layers and now have possible application and presentation specific mixed in with what should focused with domain-level responsibilities.