The Purpose of advertising can be discussed in various ways. In the first way, advertising is a way to communicate certain products to the public so as to make substantial sales. In the course of advertising for a product, you make  more sales. Advertising online is the best way to make sales for a product. The internet is the largest advertising network to sell a product online. When you advertise a product whether through the forum or google, it will continue to yield life income for you. Each advert you post to a forum will earn lots of dollars for you. Perhaps, advertising is a medium through which you bring to the notice of people, the idea of the product you are selling at a particular moment or period of time. There are many ways to advertise online. Among many ways are posting adverts to online forums, discussion boards, newsgroups, as well as advertising on google. You can also submit articles to article submission sites. These are the most effective ways to advertise for a product online. Furthermore, it should be noted that the rate at which you make money depends on how effective your advert is.Affiliate marketing is a way of marketing for a product or service of an affiliate company. As an affiliate marketer, you are paid commissions for every sale you make. For example, at clickbank, there are hundreds of thousands of digital products that you can promote online to make money. At clickbank, there are many companies that pay up to 75% of sales in commissions. To start earning money with those sites, just create unique hoplinks with the various companies that you are willing to work with. There is no limit to the amount of income you can generate from affiliate programme. Apart from the clickbank affiliate products, you can also search for free affiliate programs to join online. The best affiliate program to join is the google affiliate network whereby you make $100 for every referral into google adsense program. To start with,  you must have a valid google adsense account  before you can join the google affiliate network. Infact, this is the basic requirement. Please note that there are many affiliate companies that do ask you to pay a certain sum of money before you can join them. Do not be deceived by such  sites because you do not have to pay before you can make money from affiliate program.