Google Adwords are the fly by night one off kind of campaign.. and it lacks the visibility and the human aspect of marketing as it is only listed as a link in the Sponsored Links section on Google Search Results pages.

In Facebook, it goes beyond just numbers and links... as the human aspect needs to come in to bring the brand, product or service to live.. and not only attach it to the money and ROI aspect, but the person behind that product or service.

When coupled with a Fan Page or a Group, the member becomes attached and will also be able to interact with other people within that niche as opposed to just using Adwords to pump into a Squeeze Page.