Google AdWords is arguably the most targeted form of advertising you can do. It’s the most targeted form of advertising as people searching on Google search are telling you exactly what they are looking for, and your ad can show up alongside those searches.
As well as this, it is also pretty much the most trackable form of advertising you can do (if you set up conversion tracking on your website).
If you compare this to radio and print as an example, it is very hard to know how well they are working. If your store gets busier after running a radio or print ad, then you can assume it’s working, but can you work out cost per lead, and target the ad at different times and know which is best? What if you did print and radio at the same time? It’s next to impossible to know how well that worked.