Social should be used to drive interest.
A key benefit of Facebook is demand generation. If you are looking to build interest in your brand/products and your budget is limited Social could be a good channel.
Yes Google can create demand too with the Google Display Network but Facebook and the other social network sites, by their very nature of capturing social interaction and interests at a granular level, puts them at a distinct advantage.
Facebook can be significantly cheaper than Google in terms of Cost per Click (CPC) especially if there’s runaway interest in your post. According to AdExpresso the average CPC was $0.28 versus $2.32 for Google. But be very aware – clicks on social networks tend to have low conversion to purchase.
In most cases we recommend starting on Facebook to generate awareness, and then move to Google Ads once demand is in place and people are actively searching for your products.
We have run campaigns for clients for several years across Facebook, Instagram, Twitter and Linked In; both prospecting and remarketing. In some cases we have achieved CPCs as low as 2p, and significant revenue growth.