I was in my "Account Settings" and decided to click the "Request Credit Line Increase" link. It said that I would get an instant decision without a credit bureau pull. I figured, why not and went for it.
I've had my Double Cash card since August, with a $2,500 limit. Today, they increased it to $3,900. 
$40,000 - Chase Amazon Prime Rewards Visa
$40,000 - Bank of America Unlimited Cash Rewards Visa
$39,500 - Citi Double Cash Mastercard
$35,000 - American Express Cash Magnet
$25,000 - U.S. Bank Cash+ Visa
$20,800 - Comenity Playstation Visa
$20,000 - Capital One Savor Mastercard
$14,500 - Discover it Cash Back
$10,000 - Goldman Sachs Apple Card
