I've had the card for over a year now and I've had 3 CLIs within that time period. I PIF each month (mostly) and the reason I think I got the CLI because I placed big charges that got me close to my limit. I never requested them. Again I'm not sure and never asked.
Starting CL: 1200
CLI 1: 2800
CLI 2: 3500
CLI 3: 4200 (happened about two months ago)
I've had great experience with them. They have good phone customer service and a nice website (although kinda bland). The only problem I had with them was when it came time for my replacement card. Merrick updated my account with the new card information before I got it. That caused my Geico insurance premium to decline and I had to pay it by EFT. But customer service was really nice and told me my car insurance wouldn't cancel because it was their fault if I waited to pay.