I honestly believe that occurrence largely depends on your computer's set up especially the profile of your browser. The duplicate cards did happen once on a friend of mine - and that was from way back when we could do AA cards every 60-65 days at clockwork. Since then the little group of us started to use 2 different browsers to avoid that potential issue from happening because we wanted to get one Visa one MC. That is how long ago when MC is a regular product of AAdvantage.

It is not until years later (yes years later) such thing is being touted by many bloggers as a 2 browser trick to get 2 cards as if this would enable people to get 2 cards at the same time... What a misleading of the herds!

There is no need to use 2 browsers if your computer is set up with different profiles within the same browser. However since most are not savvy in the usage of such (me included), using 2 different browsers basically ELIMINATEs the potential problem.

Besides, one could not get more than 2 cards of any kind from Citi within the same 60-65 days anyway.

Both you and sdsearch are correct essentially just so that you are more articulated in addressing the MISUNDERSTANDING of the so-called "2 browser trick" as if it is some trick to get you 2 cards... when sdsearch, in his usual fashion, went into great length to explain the several elements related to the reasons why using the 2 browsers does have some advantage than using the same browser.

However, both of you are essentially talking about the same matter that is badly misunderstood by most.