Advantages of .NET 3.5 vs 2.0, for customers

Question

Did you ever have to persuade your customers that migrating your ASP.NET web forms application from 2.0 to 3.5 is necessary?

Why customers should install a new framework? (and sometimes a new operating system - there are a lot of Windows 2000 machines out there although support for it ended in 2010).

Which advantages for them?

• Security?
• Performances?
• Costs?

Is the only reason that 2.0 is old?

Any link is appreciated.

PS: Please don't answer that 3.5 has LINQ, it's an advantage for developers not customers

Answer 1

The advantage here is indirectly for the customer, by (hopefully) allowing you to write code faster/shorter and therefore fewer bugs and more deadlines hit.

There may also be small performance increases with the newer iterations of the franmework.

Answer 2

Actually, .NET 3.5 is still using .NET 2.0 as its base, just several add-on.

For old applications, deploying .NET 3.5 have no use. You will only required to install a specific version of the .NET Framework if you're application was created for that.

Anyway, LINQ and WCF are the great add-ons in Framework 3.5 that provide better performance and interoperability. ;)