One of the primary reasons I use Blur is for the virtual card feature. I do a lot of purchasing online, and regularly deal with theft of CC numbers. - which means filing disputes, cancelling the card, and waiting for a new card to arrive.
My CC provider also offers virtual cards, but they've often been problematic (charges flagged as fraud, VERY slow support, etc) the first time out.
So far, I haven't had a problem using Blur's masked CCs, and it's a real load off my mind to know I can avoid scammers when buying online.
Also, so far, Blur's email support has been fast too.