For me, depending on the person/situation, (e.g. I'm chatting with someone in the grocery store or something), I usually just advise that any canned is better than dry, because of the moisture content. For me, the priority is just to get the cat off the kibble. Then I hand them a little card that has a list of feline nutrition sites (catinfo.org, etc.) and this forum
and strongly encourage them to check out catinfo.org. It's up to them to go from there.