I had a card for years with them with a decent $5k limit. Because I began using other cards and my balances were getting higher, they started inflating my interest rate without a word. I never paid late, and my fico score kept getting better during this time (I bought a house and used my other cards for some renos). I finally paid them off entirely. After 6 months of not using them, they canceled me due to inactivity. That's my experience with Direct Merchants.
