E-commerce and any other business model online is just as good as any offline business model and equal, if not more effort might go into your online business than your offline ones.
If you were blogging for example, any blog would usually take about 6-8 months of intensive posting and that too very consistently to be able to show itself on search engines and get indexed organically. In fact, with the sheer number of blogs online today, you would need more than 2-3 years now. Not only that, to be able to make some kind of money from monetizing the blog, it is critical to have a regular and consistently high traffic. This would undoubtedly take time and effort.
Assuming you just wanted to put an online store, you’d still have to promote your site until it gets enough traffic to purchase your products. You will have to engage in a mix of marketing efforts, both online and offline.
You’d have to give your online businesses the same importance as you would attribute to your offline business, if you did have one. Most people give up too soon due to lack of patience and their refusal to accept embracing an inevitable learning curve that accompanies your growth to online business mastery.
You sell – information, services or products. Period. There might be some more ways that work around these three, each of them or all of them. However, clicking links, reading emails and stuffing envelopes isn’t what you should be doing to be able to make some decent money online.