I was wondering if it will harm my business much if I decide not to accept American Express & Discover credit cards on my website. These come with extra applications for my merchant account and I would think that most people have a Mastercard or Visa... what are you thoughts on this?
A few years ago, I faced this same choice and decided to spend the extra money and get the other two accounts. It does cost more to get the accounts and they also take a little bit of a larger percentage, but I feel that it was the right thing to do. I do just as much business with amex as I do with mastercard. And it really is not about people having a visa or mastercard, but it is also basic preference. A lot of different cards have their own reward programs and perks and some people prefer to use those cards for everything. (I know I am like this with my amex.) You must also consider that if you don't take them and your competition does, that would be hurting you a lot. Just my two cents though.
Depends on your business. If you plan on selling to other businesses at all you sure as heck better accept American Express as it is the defacto business card for most US businesses. If your primary market is not even close to being business related then you probably could easily not accept it without major repercussions. As far as Discover Card goes right now not accepting them isn't a big deal. But, now that they are changing how they operate and are having acceptance of their card integrated with Visa and MasterCard with many processors, demand to accept their card is going to increase as they reach more and more merchants. In the future they will be in more demand although almost certainly they will still be #4 overall. Considering that Discover Card only charges a small application fee and then you never pay them a single cent again unless you actually accept their card I don't see why you wouldn't want to sign up now and then not have to worry about it in the future.