Last week I tried 61 days CLI thing on my Discover card - went from $1K to $1.3K. Not too much, but I'll take it anyway, since I don't use this card a lot.
Also, today I was checking my BofA online app as I do every morning, and saw that they returned my initial deposit for secured card ($1K) and gave me CLI from $1K to $3K!!! That is awesome, I wasn't expecting anything like that from BofA.
So, I went from $1K in credit limit this summer, to $6.3K in March. And I still gonna try to get 3X CLI on my AMEX somewhere in April.