Manish Singh

The answer is "depends" :-)

It depends on what kind of promotion you plan to launch. Google adwords works excellent for direct sales where advertisers bid on specific keywords and send the highly targeted traffic to a specific product/landing page. It gives quick ROI on the money spent.

On the other hand, Facebook is a community website where people generally come to socialize and not buy. Hence the buyer's "intent to buy" is not present when he/she clicks on your ads on Facebook.

Facebook, however, offers very specific targeting. For example, you can target all Male members above the age of 18 from a specific area with a specific interest. Google Adwords does allow geo-targeting, but it doesn't give filtering based on user age, sex or other preferences.

Although the targeting can be very specific at Facebook, there may not be an intent to purchase your service. For example, you can run your ads to all male members above 18 years of age from a specific area about a local dating website. However, not everyone who sees such ads may be interested in the service. So how do you protect yourself as an advertiser from such clicks? To counter this issue, Facebook also offers CPM (Cost per thousand impressions) based pricing. CPM based advertising also works best in case the promotion is for branding purpose and not intended for sale.

The best campaigns where Facebook ads work good are "Like" campaigns for a Facebook page. A facebook like on a page makes the user a fan of the page. A Facebook fan will return to your page and keep a check on latest updates posted on your Facebook page. Hence the returns on such campaign last even after the ad campaign ends. This is not true for Google adwords where visitors simply click-buy and move on. As soon as the campaign ends, the flow of visitors stop. Unless they have specifically subscribed to your website newsletter or ordered something from your website, there is absolutely no way to get in touch with such users.

Also given that the Facebook system is relatively new, it is still cheaper compared to Google adwords where cost per click on some of the most competitive keywords exceed $30 USD.

In conclusion, each advertising platform has its pros and cons. Google adwords works best in a sales promotion and offers a quick return on investment (ROI) whereas Facebook ads work best on socially aware promotion campaigns where the users have an opportunity to engage with the brand/company. This may or may not result in an immediate sale.