Tuples are a great example that I might not have thought of -- you practically "define" your own value types all the time. Also, all enum types are value types.

Tuples are a great example that I might not have thought of -- you practically "define" your own value types all the time. Also, all enum types are value types. And there are lots and lots of very commonly used value types in the base class library: DateTime, TimeSpan, Guid, CancellationToken. Programmers have to be familiar with their semantics.