One of the things that many online retailers don’t seem to realise, particularly those that are not household names, is that people are more likely not to trust them then to hand over their credit card details without thinking.
There are far too many websites out there who expect visitors to trust them and buy from them for no reason. There are thousands of fraudsters out there as well and the number of both is growing. You simply cannot sit back and wait for people to come to you and buy, (I know I’ve said that before), you have to demonstrate that you’re trustworthy at point 1 when they arrive at your website so that they're in no doubt at all.
If you’re a household name then of course people will trust you. If you’re not, you need to show in any way you can, and as obviously as possible, that you are to be trusted.
So show the payment methods you take. The security measures you have in place. Your membership of any accreditation schemes such as ISIS from IMRG (Internet Shopping is Safe) and any awards you have won. And do that as soon as possible. Don’t take anything for granted, particularly where trust is concerned.