8 months ago, my wife and I were starting to build our own business. We didn't create our own products, at least not yet for now, what we do is just reselling others product. We didn't open offline store at all, but we use facebook as our commercial web to display the products that we sell. Besides the features that given by facebook, We only added extra communications way using sms or bbm. Amazingly, we could earn back all capital that we spent at the beginning in only 7 months. What I want to ask is Do we still need our own website since with facebook we can do sells? I'm afraid if we build our own website, the web won't be used as it should be, because we still can do transaction easily using facebook. Besides that, building a website is not an easy thing.
You have a successful trading business on Facebook. That's one business, and you know it well. Now you need to ask a different question: is there an additional opportunity to build a whole new business on a standalone website?
This is all about reaching different customers. On the plus side, a lot of the experience you have built up on facebook will be directly transferable. On the minus side, you don't have experience in this area and there's a risk it takes too much of your time and damages the existing business.
So my suggestion is, start by carving out some time (rather than money) to do some Googling. Find services that offer you a simple, minimally customized e-commerce site and that don't ask you to sign long contracts or put a lot of money up front. Plenty of these will give you a free trial, and maybe extra goodies such as Adwords credit.
Your learning objective is: can I come up with an affordable (time and cost) experiment that will get me a fully functional site and test the market?
If the answer is "no" (and that should be the default), learning is never lost - and you can double down on your facebook business with confidence.
If it's yes, be disciplined and give it a go. Don't over-invest time or money while you validate, and be prepared to shut up shop if it's clear that there's no net benefit (for instance, a lot of online stores spend more on advertising than they can make from a first order and depend on life time value - and it's hard if you find yourself in a category like that).
But you may find you're reaching new customers and adding new profit. Because you've gone step-by-step, you can make intelligent decisions from the data, and gradually develop your fledgling web business alongside your established facebook one.
Good luck! It's great to hear a success story, and you're right to combine caution with your entrepreneurial flair!
Like many things in life sometimes one size does not fit all. You are selling successfully on Facebook. Others use eBay while still others build their own eCommerce website.
Clearly all the above (and much more) can work. The real question is what works best for you?
You state: "Besides that, building a website is not an easy thing." That is undoubtedly true for you. For others, web developers for example, it may be trivial for them to build their own eCommerce website.
So my advise is to continue doing what works for you and make money.
One caveat however; the internet evolves very rapidly. Facebook has not always been here and certainly in the future there will be new opportunities that no one has even thought of yet. Don't become complacent; in the future you may very well want to sell on other properties beside Facebook. That may or may not include an eCommerce website of your own.
In order to grow your business creating your "own" web presence is probably the right thing to do. If you have reached ROI by now, you should be in a good position to make this investment. I'd see several advantages:
The big caveat though is that you should be careful when moving your sales process from facebook over to your own e-commerce site. Especially when the largest portion of your customer base is used to interact with ou on facebook, they might be baffled when they are suddenly redirected to your own site. Make sure the experience feels integrated and is as seamless as possible (e.g. offer to browse products in a facebook iframe and then redirect only for checkout).