I agree with the sentiments expressed by many here. You need to take a look at your business and examine your habits before jumping in.

How much you can earn via credit cards depends a lot on what type of business you are in. If you are paying cash (which is not at all the same as paying with a check) then you may get a lot of resistance from your vendors to using credit cards because cash is a resource they wont want to loose. Checks can be traced and Cash can not. So if you are truly paying cash I would be surprised if your vendors will let you switch to Credit Card payments with out a fight.

So if you are in the restaurant business and you are going down to the Fish Market and the Wholesale produce market and that is where your money is going your chances of switching your purchase power to a credit card may be fairly low. On the other hand if you are buying stuff online and from Vendors you know take credit cards then that is a whole different matter. As mentioned above those credit cards charge a fee to the vendor so that means that they might also raise your prices if you use the credit card. Many of my vendors give a 2% discount for a check vs. a credit card. Find out before you switch over.

Also know that Amex charges a higher percentage of the transaction than Visa or MC to the vendor so many will only take Visa of MC. It's about 2.5% of the transaction on Visa or MC but 3.5% of the transaction on Amex. When my customer try to pay ME with Amex I always try to steer them to something else to save that extra percentage point. This might mean you get both and Amex and a MC.

Much depends on what type of business you are in and whether or not your Vendors find you to be an anomaly or business as usual. Do your homework. On the other hand you need to also consider what habits you can change to max your CC spending. For example do you go down to Costco when ever you need something and buy office supplies with a check? Consider buying from Staples or Office Max with a CC and waiting to purchase what you need till you have a $150. order so you can order online get free delivery PLUS a spend with a CC. You need to examine your business and your habits to make the most of this opportunity.

One more thing: Pull your own Fico score at myfico.com before you apply. You think you have little credit: you should find out for sure before you go this route. You may have better credit than you think (or maybe not). It's worth $14.95 to know so that you either choose to build your credit if you need to or you apply in a way that makes sense to your situation!