Well, marketing itself is not only about Google and Facebook.
Digital graphic design can be used for printed advertising as well. What else?
Another option is sponsored advertisement usually requiring its configuration that varies based on the selected search engine (Google PPC) or application (products comparing apps).
Setting up subscriber’s sign-up feature and configure a template for regular or even automatic newsletter advertising is another option your customers might welcome.
Monitoring & Google Analytics
You would be blind without a monitoring solution. Set up a Google Analytics or similar tool is an essential step to understand your customer’s behavior, traffic channel, entrance page, point of interest, and other useful information.