Online advertising is all about visuals supported with attractive introductions.  In the past also you were using visual ads to promote your ads or services. But they were available only when someone took the pains to visit the theater hall to see your ad movie or sat before his TV set at a particular time to see your ads. Internet surfing has solved all these problems. Now your ad is available to any viewer sitting comfortably in his drawing or bed room before the Computer at a mouse click or key stroke. And if you want to economize your ad expenses while not cutting into the benefits of the publisher, the Pay per click advice may come up quite handy. 

Common methods adopted for online advertising are Cost per Impression, Cost per Visitor, Cost per Action, Cost per Delivery, Cost per Conversion, and of course the Pay per Click. However with Pay per Click help readily available with most popular search engines, the same may be the most convenient way of promoting your ads online. 

Cost per Impression or CPM aims to contact a specific audience and Cost per Visitor or CPV aims at a targeted visitor. Cost per Action or CPA is a tool for affiliated marketing and seo while Cost per Conversion or CPC is difficult to calculate as you rarely know when a visitor becomes your devoted customer. That is why major Website design services prefer Pay per Click as your ad promoting tool.