The only reason to run a balance is to increase credit rating (which is a total scam anyways... No credit history because you've never been in debt? Sorry can't approve a house/car loan. WTF?)

I use mine, similar to your description, with a max balance of 5% of the card's allowance. It keeps the interest payments low but, increases credit rating. There are key things to remember: have 2 cards, "lock" the max balance of your primary card at the 1000(enter appropriate currency symbol) mark just above your weekly paycheck, use the 2nd card only on buy and pay off immediately purchases... About once every 3-4 months.

The first card maintains credit reliability, boosting credit score.

The second card will increase in credit limit (in addition to the fixed limit of the first) boosting credit score.

Having a low limit, locked card for primary use, is "safer" if credentials are ever stolen. (No waking up to find 10k worth of charges).

Having low usage on the other card lets you and the CC company easily identify false purchases.

Having two cards increases the total "account age" portion of your credit score.

It's a scam. But if you plan to buy a home or vehicle (and not get ass raped by finance companies) you have to play their game. It will help to lower loan rates on SPL'a also, but if you rarely buy outside your means, the difference is negligible and just take the higher rate on the loan. (Figure ~200+ minimum to increase credit rating per year vs 5-10% more interest on a SPL... You'll be spending more, overall, on credit rating than rarely using SPL's).

The only thing that has impacted me was a house loan and emergency car purchase... If you aren't planning on buying a home, completely disregard "credit rating" and do as WorldLeader describes. (Just be sure to stop the auto credit limit increase please)