Among credit card reward enthusiasts, the strategy of applying for numerous cards in order to earn multiple sign-up bonuses is called credit card churning.
Surprising error, inasmuch as the author is an active Flyertalk member.
Churning is the practice of applying for a credit card, earning the new account bonus, cancelling (usually), and reapplying
for the same card. There is no churn until the second application for the same card.
Applying for several cards simultaneously is an App-O-Rama (AOR).