Sharing is caring as a motto between friends:

If friends go by this motto, they share a post or repost something that was funny/enjoyable/interesting, so that their friends can see it too, enjoy it and comment on it or discuss it with eachother. So sharing something with someone means that you care about his/her enjoyment, want some feedback or a conversation about the subject matter or want to inform him/her about something you have learned or seen.

Sharing is caring as a motto between company and customer:

In the context of the OP this motto works too, but is of course a little more specific. What is being shared is information about the company that the customer might want to know (new products, price drops, changes in policy etc.) and the people who are being cared for (by being informed/receiving information) are the customers who follow the company (via platforms like Facebook and Twitter for example). Keeping your customers informed via networking platforms, even if the information is only trivial, can keep your brand or products (seem) relevant, help win over new customers and also keep your regular customers loyal.

I hope that helps a little bit with the meaning of "sharing is caring"?

Remember that the word "care" means a whole bunch of different things: Umsicht, Sorgfalt, Betreuung, Pflege, Zuwendung, Achtsamkeit...

(And there's also a difference between "to care for" and "to care about".)

So you could say that "sharing is caring" in this context is supposed to mean something along the lines of:  

"Information teilen bedeutet gute Kundenbetreuung"

"Mitteilen bedeutet den Kunden Zuwendung zu geben"

"Mitteilsamkeit ist Achtsamkeit" ...

Mitteilsamkeit ist Achtsamkeit" -- leider geht das nicht, Vulthoom (nur dies rausgegriffen, weil ich es gerade sehe).

'mitteilsam sein' heißt im Grunde: (zu) viel reden.

#2 und #3 klingen noch ziemlich unbeholfen.

Habe jedoch gerade auch keine bessere Lösung...

Ist okay, Vulthoom, ... ich profitiere übrigens immer sehr vom Lesen deiner posts.

Und jetzt muss ich dein 'waffling' nachschlagen... ;-)

(Edit: Ah, es heißt 'Geschwafel, Herumgeschwafel', z. B.)

Thank you for the pat on the back. That feels mighty fine and I'm well chuffed about having been able to help somewhat. :)

I also learn a lot by reading discussions in this forum. I understand enough German to work in Germany, but I would really like to get a more intuitive understsanding of the language and German culture. This forum helps me a lot with that. Most of the regulars and the Leo team can be proud as punch that questions and queries are so often answered lickety-split. You have a fantastic network and I'm very happy to be a small part of that :)

#12, ein sehr schönes Feedback für alle... (noch off topic)

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Zur Anfrage selbst fällt mir jetzt ein:

grad zufällig gefunden zur Unterstützung des schönen Vorschlags von Braunbärin:

Teilhaben durch Teilen

Teilen ist Kümmern

verändert

Nehmen heißt Geben / Geben heißt auch Nehmen

Wer nimmt, muß etwas geben

Wer gibt...