We have our choice of ways to communicate in this age. Coffee mug chalkboards may not be the most efficient, but they can get a fun point across -- like "Hey! You're cute!" or "Don't look now! There's a hipster riding a fixie behind you."
Hipsters would not buy these mugs, but they might mooch one from you. (Just kidding, hipsters! By the way, one of you owes me a snap shirt.)
Blackboard mugs have a certain appeal to me. Here is a great medium for cute love notes, or something silly.
Life need not be urgent all the time. Urgency is why we have smartphones (which mostly get used for non-urgent stuff!).
Simple, relaxed living -- that's why we have chalkboard coffee mugs.