When to use services [Answered]

This might sounds like a weird question, is it worth using services in a small-ish non-server console app? I haven't really ever used services (nor DI) to any extent since I've never done anything with ASP.NET or server-side, but I'm just wondering since a lot of people seem to talk about services quite often. How do you know when you should use services as an integral part of your architecture?