Most companies spend a significant amount of their sales income marketing their product. The internet is one of the most cost effective ways to increase the market share of their product. However, except for a few countries like USA, Canada, Europe, Japan and Korea, there are few relevant websites for a wide range of products and categories in most countries.

By providing useful information to visitors to your website , you can easily earn money from your website, without much additional effort . Unlike other mass media like television & newspaper, your website can be built at a very low cost - less than $50 a year for a basic website but you will have to devote a lot of time to developing the website.there are many sites whih help you to build a website.
Advertising networks like Adsense (Google) , Overture (Yahoo), Commission Junction, Chitika (eMiniMalls) pay owners of websites to display advertisements. Microsoft started a contextual ad program - ContentAds in 2006.
http://www.jensense.com/archives/2006/02/contentads_the.html
Most advertisers on Commission Junction, however run affiliate programs.
1)If your website has sufficient general information in your product category ('content' ) or hard to find information , you can apply online to any of the advertising networks . The website should be preferably be registered in your name or your company name.
2)you can earn money even from a website with low traffic.
3) Some advertising networks do not accept website owners (publishers) from some countries (including India) . Others only consider websites with several million visitors per month. For example Chitika, clearly states that it will discount all clicks from visitors in China, India and similar countries. Many web publishers have lost 50% or more of their income after such "invalid" clicks were deducted from their account after audit . The program from Yahoo for smaller websites has a similar limitation and is currently open only to US residents.
4)If your application is approved , you will have to paste the tracking code on your website.
5) You will be paid on a CPC (cost per click), CPM (cost per thousand impressions), or pay per lead or sale basis . The CPC / CPM will depend on the number of advertisers in a particular product category. Many banner networks offer a CPM of US$0.5-1.5 , but with some CPC networks , you can have an effective CPM of US$4-5. So if your website has 3000 visitors a month, 10000 page views, for a CPM of US$3 , you could earn US$30 every month. Not much, but enough to cover web hosting costs. Not many companies offer pay per lead or sale for websites outside Europe & North America and this method has the lowest conversion rate.
6)To protect the interests of advertisers most advertising networks have fraud detection software in place and will disqualify publishers suspected of clicking on advertisements on their own website.
7) Earnings from online advertisements can be substantial, and many large publishers earn several thousand dollars a month from advertising revenues alone.
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