If you’re just beginning with ecommerce, you’re right to be excited. The prospect of success carries a number of alluring promises with it. That 
doesn’t give you an excuse to be reckless though. Many promising eCommerce websites die prematurely because their creator dove right in when they should’ve thought a bit longer. To help you avoid problems early on, here are some mistakes you’ll want to be careful to avoid.
In an effort to stand out, you may create a website that is overly complicated. Design sites are notorious for this: they want to show off what their services can do, but in the end, they just create a maze of animation and scattered copy. You always want to stand out from the competition, but website design is pretty set in stone. The typical arrangements you see are used because they’ve been proven to work time and time again. Take a look at how your top competition has arranged their sites and follow suit.
A well-designed site isn’t worth much if it won’t load though. Hopefully, you’ll avoid this problem if you keep things simple, but large images, animations and more can force your webpages to take an eternity to load. Actually, if they take as much as three seconds, studies have proven you’ll most likely lose business.
There’s no doubt that competition is fierce in most online industries. So it’s tempting to cut costs wherever you can. Many sites pass on shipping to the customer, for example. However, others try to handle the shipping themselves and then overcharge their customers for the service. Typically, if you’re charging more than 10% of the total price for shipping, you’re going to chase away customers. Even 10% is pushing it too.
Another mistake having to do with the purchase is forcing customers to register in order to check out. Very few customers will want to do this, especially when they probably have plenty of other websites they can buy from. Often, registration won’t be worth the hassle anyway because customers have become accustomed to handing out throwaway email addresses they never check. If you want people to register with your site, incentivize them somewhere, but do it away from the shopping cart.
The above mistakes are easy to make and are often the result of good intentions. That being said, they’re mistakes all the same and can cost you money. While this is never a good thing, it’s especially detrimental to someone who’s just getting started.
Source:
http://mashable.com/2012/04/12/ecommerce-mistakes/