I app'd for the Citi DoubleCash card and was immediately approved for $4300 and didn't do anything until I received the card in the mail. Once I setup the online account I clicked on the credit line increase button where it asked me for my yearly income, mortgage payment and credit line desired. I asked for $20k and I got a message that they need to review the request and get back to me within 24 hours. The next day I got a brief email that they reviewed my request and were able to increase my limit to $9300! Nice little bump before I've even used it.
Nice job! Congrats 
I did the same thing when I got mine. SL $4500 -> $6000
Not sure if that was worth another HP, but it's something. Next time I'll wait for the SP screen.
Congrats, looks like someones on Citi's good side