Regarding convenience, that is why money and digital currency exist, it's more convenient than gold.
Again, how is veribit different than me taking another coin, say DRK, and exchanging it for btc on mintpal to make a purchase? Veribit doesn't revolutionize anything. And guess what, both methods will take a similar amount of time and effort to make a purchase. But Veribit has a 1 btc max right?...
Veribit is a gimmick and nothing more.