Depends on your product, but in general I recommend you have some method to accept credit cards, because if you don't it will damage your chances to make salesWhy? Because many people buy on IMPULSE, and if they figure out your bank details, go to the bank, arrange a wire transfer, etc., by then they've probably lost interest or found somebody else to buy from.
By the way ClickBank and Verotel are not merchant accounts
A merchant account means you bill the customer's credit card directly and the money goes to you directly. There are various online services to arrange this (mostly US only), or you can arrange this with your bank. You may be credit checked, etc., and/or to prove the viability of your business, and/or to make a personal guarantee to the bank.
Clickbank and verotel are billing services or payment processors. They bill the customer, and then send you money in arrears. For these types of services, there is usually no credit check, but the fees per transaction are higher. You also have to wait to get your money, and there may be additional restrictions (example: ClickBank's rules). BUT the good part is they are easy to setup, they work, and don't cost much to get started. This is a good way to dip your toe in the water, and if your business grows then get a merchant account. In fact, I have so far stuck to ClickBank, and not bothered to use a true merchant account (the bank even visited me to offer one) because of their affilaite tracking and other features.
There is more info on accepting credit cards including terminology etc. atwww.merchantkit.com
