I just clicked the CLI "Luv" button on my Citi Platinum Select account page. I've had the card for about 9 months, originally used it for their BT offer. Opened the account with an $1800 CL, used their BT 0% APR offer and paid that off before the offer expired. After a few months, they offered a 1.99% APR BT offer, so I again took advantage of most of my available credit. It's the first month of using the BT, so I have a $1,600 balance at 1.99% APR, $1800 overall limit. For the heck of it, decided to click the CLI button. Like the other user on this thread, the next page asked for a figure of the requested increase you prefer, along with your annual income and employer name. Page also said that you authorize a CRA to pull your credit history. Next page confirms your selections, again has the little blurb about the CRA.
Third page confirms my CLI request (I requested a $2000 increase) and also states that a report was not pulled to determine and offer the CLI. They were able to double my original CL, so from $1800, I received another $1800 bump (compared to my shot in the dark $2000 increase request). Not bad if I say so myself considering I was already carrying a $1600 balance. Current CL is now up to $3600. 
In case anyone was wondering, after the automatic increase, there was a button on the bottom that said "Request More" which redirects you back to the first CLI request page. I'm assuming if you go through it a second time, a hard pull would be done.
