According to Wikipedia:

App-O-Rama refers to a strategy of completing multiple credit account applications in a relatively short period of time. The term, as set out in the Wall Street Journal, refers to a frenzy of applications, and most frequently refers to applications for financial products, such as loans, credit cards, and bank deposit accounts. However, it can also include insurance applications, brokerage applications, etc.

Applying for many credit cards at once to take advantage of signup bonuses and introductory balance transfer offers.