I hereby decree that anyone with the impertinence to convert any artwork I send them into JPEG for display on the hinterweb shall be stripped, tarred, feathered and otherwise humiliated in whatever public arena I deem suitable.
If I send you a PNG file it is for a reason. It is beacause the PNG format is wonderful. The reason I rarely send out stuff as JPEGs is because JPEG is horrible. JPEG is for photographs displayed on the web and that is it. It is not for anything else. You see that nifty little logo I sent you that now has jaggy bits and artefacts and all manner of extraneous rubbish all over it? You did that when you inexplicably converted my shiny new PNG to JPEG. It was good and now it is shit. Thanks for that. You've made us both look like idiots.
If I send you a PNG file please, please, PLEASE just leave it alone. If I send you a PSD, a PDF or an AI file and you want to display it on the web either save it as a PNG file or ask me to do it. I will gladly oblige.
Converting my work to JPEG makes me cry and then I have to drown my sorrows in bourbon and then I miss work, end up jobless and homeless and possibly dead in a gutter with my shorts around my ankles and my lifeless member being gnawed by rodents. You did that.