I only use Pay Pal. Why? It's widely accepted (many people have PP accounts), it's easy to use and hook up to just about any site or system, piece of mind because all the financial details are on PP's site, not mine, and last but not least, I can get my money at any ATM any time. I can also call them any time if I have a issue or question. They've always had great support.
Do I lose sales because I only use Pay Pal? Sure I do, but it's not great amounts. I feel it's a good trade off for the above. And honestly, for some (maybe most) who can not pay through pay pal, they probably can't pay though other options anyways.
And Pay pal does have the option to pay with most any credit card or debt card without needing a PP account.
You
DON'T want to take credit cards or use your bank as mentioned above. That is a
BAD idea. Taking credit cards means your site stores credit card details, which means if your site is hacked, you could be held responsible for other peoples personal financial details. If Target and Home Depot can get hacked, do you think you stand a chance of not getting hacked? The bad guys are looking to get into to any site, big or small.
Plus, if go with your bank, that means a merchant account which means a credit check, higher fee's, and again, your probably storing credit card details.
Also, when you spread out the payment options, it could take longer to get your money. Some places take a week or two to give you your money.
Years back I tried Google Wallet, or what every it is being called today, and got stiffed on two out of three orders. Maybe they've changed, but I have not had a good experience. Last I heard they don't even have phone support.
For th average person looking to sell some things online, Pay Pal is a great option. If your talking about big business, then yes, other options should be explored. But for most who work from home, it's not worth adding to many different options.
Of course I am not a payment expert, just my opinions. If I am wrong or some one want's to add an intelligent reply, please do