pollicitis dives quilibet esse potest - Ovid, Ars Amatoria I.444
"Anyone can be rich in promises." (lit. "things promised")
In this section of the Ars Amatoria, Ovid advises the prospective lovers how to avoid spending money on gifts for their girlfriends. He advises they promise to give gifts, that way they don't have to actually give anything. As he puts it:
at quod non dederis, semper videare daturus:
sic dominum sterilis saepe fefellit ager.
- I.449-450
"But that which you haven't given, may you always seem about to give:
Thus has a barren field often deceived its master."
So, naturally, I thought of Credit Cards.