Any business that gets some or all of its customers or clients locally should consider local SEO. That should be a local restaurant, retail outlet, doctor, dentist or lawyer, but it could just as easily be a local ad agency. If you have a physical address in a city and expert people to go there, you should be doing local SEO for that location.
Local profile on Google
While all of the factors that apply to regular SEO also impact local SEO (on-page factors, links, content indexing, etc), local comes with a few unique elements. The first and probably most important is that for local SEO you need to create and claim a local profile on Google (and other platforms as desired). Your listing is what will usually show for localised search results.
The second most important thing is called a NAP citation, which is any place online that uses your company name, address, phone number. Google views NAP citations in the same way as regular SEO views links – citations from authoritative and relevant sources can help improve your ranking. While Google is very smart, it is important that all citations use the same format as far as possible. Do not abbreviate in one and not the other (St versus Street, for example).
Third, you need reviews. Lots and lots of reviews (preferably really good ones). The quantity and quality of reviews left for your business on your Google Places page is one of the most important local ranking factors.
The three biggest factors in local listings appear to be the number of citations, the number of reviews (primarily on your Google Places listing, although other places do count), and how positive the reviews are overall. Positive reviews will trump citations, so persuading your customers and clients to recommend you on your Google local page is the single most important thing you can do.
Ryan, D., 2016. Understanding digital marketing: marketing strategies for engaging the digital generation. Kogan Page Publishers.