First, be sure that you have a well-defined audience or community in mind. It will be difficult to judge the efficacy of your marketing if the target is largely abstract or only half-considered. But even with a well-defined audience, it can be challenging to firmly determine the effect of marketing.
One of the best ways to ensure coverage is to do it directly with the people you wish to reach. Combining marketing with direct community engagement helps to inform that community and involve them with the new installation. It also offers the commissioning agency reassurance and confirmation of their outreach efforts. And, as with all forms of community outreach, working with community stakeholders, representatives, and organizers will help to ensure that your message is heard.
For larger and harder to define groups of people, like tourists, a city’s visitor’s bureau (or similar type of organization) can offer suggestions and advice on marketing, and may be able to directly assist with efforts to do so.