Currently, when you ping someone, there's no indication that it worked - the formatting of the text doesn't change. It would be nice to have some sort of styling on pings, like a highlight or having them be linked to the user, to make it clear that the user has been pinged. I couldn't figure out how to ping a user, but then found out that the usual @ (username) works, it just didn't look it was working so I assumed it wasn't until they pinged me back and I got the notifcation.