Are you referring to Google's Display Network when you use the term Adsense? The Display Network is how they refer to the network of websites that have codes on their site to show Google ads.
It would all depend on which websites and at which audience you were choosing to market. Graphic design is an incredibly competitive niche and it is one where people will commonly click your ad to look at your work, even when they are not interested in spending money. You will need to have a very good landing page in order to convert the traffic that comes in.
Facebook sucks for marketing unless you want people to "like" a page.