E-Commerce is playing a very essential role in the online business world. Although it is one of the best and cheapest intermediate ways for reaching out to new customers in the online market, but, if e-commerce implemented effectively, it also offers a smart way of doing online business & expanding it more. Furthermore, e-commerce is planned and implemented to provide customer with a convenient, satisfying and protected shopping experience.

Advantages
1. Being able to conduct business
E-commerce systems can operate throughout the day. The physical storefront does not need to be open in order for customers and suppliers to be doing business with the company electronically.

2. Access the global marketplace
The Internet spans the world, and it is possible to do business with any business or person who is connected to the Internet. Simple local businesses such as specialist record stores are able to market and sell their offerings internationally using e-commerce. This global opportunity is assisted by the fact that, unlike traditional communications methods, users are not charged according to the distance over which they are communicating.

3. Speed
Electronic communications allow messages to traverse the world almost instantaneously. There is no need to wait weeks for a catalogue to arrive by post: that communications delay is not a part of the Internet / e-commerce world.

4. Marketplace
The market in which web-based businesses operate is the global market. It may not be evident to them, but many businesses are already facing international competition from web-enabled businesses

5. Opportunity to reduce costs
The Internet makes it very easy to 'shop around' for products and services that may be cheaper or more effective than we might otherwise settle for. It is sometimes possible to, through some online research, identify original manufacturers for some goods - thereby bypassing wholesalers and achieving a cheaper price.

Disadvantages
1. Time for delivery of physical products
E-commerce is often used to buy goods that are not available locally from businesses all over the world, meaning that physical goods need to be delivered, which takes time and costs money.

2. Physical product, supplier & delivery uncertainty
In some aspects e-commerce purchases are made on trust. This is because, firstly, not having had physical access to the product, a purchase is made on an expectation of what that product is and its condition. Secondly, because supplying businesses can be conducted across the world, it can be uncertain whether or not they are legitimate businesses and are not just going to take your money. Thirdly, even if the item is sent, it is easy to start wondering whether or not it will ever arrive.

3. Returning goods
Returning goods online can be an area of difficulty. The uncertainties surrounding the initial payment and delivery of goods can be exacerbated in this process. Will the goods get back to their source? Who pays for the return postage? Will the refund be paid? Will I be left with nothing? How long will it take? Contrast this with the offline experience of returning goods to a shop.

4. Privacy, security, payment, identity, contract
Many issues arise - privacy of information, security of that information and payment details, whether or not payment details (e.g. credit card details) will be misused, identity theft, contract, and, whether we have one or not, what laws and legal jurisdiction apply.

Related Links:
1. http://www.smarte-commerce.com/advantages-of-e-commerce-in-present-business-scenario/
2. http://www.marcbowles.com/sample_courses/amc/ec1/ec1_3.htm
3. http://www.isos.com.my/ecommerce/advantages.htm
4. http://wiki.media-culture.org.au/index.php/E-commerce_-_Overview_-_Advantages