Well interest on credit cards doesn't hit until a month after your next statement after the purchase. For instance my statement is on the 27th, so this won't be on my statement until Nov 27th, meaning I won't be charged interest if I pay it off in full by Dec 27th. I've been using my discover card for 10 years like this, always paying the balance off in full before the next statement. I average $300-400 a year in cashback bonus from using it and have never paid a dime in interest. They're great tools if you're disciplined.
HALO:MCC >>>>>>> Interested in Online Customs, Squadmates for Ranked, and Co-Op Campaign. I am on 6am-4pm GMT on my nights off (Midnight-10am US Central). Copy this signature with your play times so we can populate our friends lists with fellow Halo:MCC players BEFORE launch!! If you add me do it on XB1 please; my 360 friends list is nearly full.