The concept of a full App-O-Ramas is applying for dozens of credit cards in a short period of time. In theory, if you apply for multiple CCs from the same issuer in the same day, it shows up as a single hard pull on your credit report. The more hard pulls you have, the lower your credit score, and this strategy is designed to maximize how many CCs you get while maintaining relatively few hard pulls.
I never got into this and prefer a minimal approach. There are some great CC signups that occur such as the current Chase Ink Preferred 80,000 UR point bonus after $5k spend.
My method is to sign up for 2 to 3 credit cards per year, with a stronger preference on business cards because business cards generally do not report to Credit Bureaus and appear on credit report. Since these new accounts will be cancelled after the first year to avoid annual fees, the use of business cards will prevent a bunch of new accounts with short histories from appearing on your credit reports. That keeps your average account age high.
I keep all of my credit bureaus frozen for security reasons and to prevent aggressive banks from pulling all three when they really just need one. Or from car dealerships from pulling ten times on the same report instead of just once. There is a $5 to $10 fee to freeze/unfreeze everytime you do it, so I tend to do my “AOR” during the same 30 day period that I do my annual 2 to 3 applications.
Next trick is to find banks that pull on different reports if possible. Chase and AMEX tend to pull Equifax. USAA pulls TU. If you can split your 2 to 3 annual applications across all three bureaus and only get one pull per bureau, then you can get 6 new CC every two years and only have 2 hard pulls per bureau report.
I like my method because it lets me get the absolute best credit card bonuses with the least effort and least risk of damaging my credit or adverse action by banks.