ATC asked that we send this recent Briefing Sheet, normally issued only to airline pilots, to General Aviation (GA) pilots as well. As you can see in the 1-page document, ATC wishes that pilots are aware of the problems caused by not reading back their call sign.
The Briefing Sheet is available here: https://www.faasafety.gov/files/notices/2012/Dec/ATSAP_Briefing_Sheet_(December_20_2012).pdf
Let’s all remember that when operating IFR or at an airport with a control tower or when using VFR Flight Following, including your call sign when responding to an instruction from ATC is the best practice!
Have a safe and enjoyable New Year of Flying!