This is one of the most effective factors for Goolge Maps SEO. Including keywords in the categories improves rankings dramatically. It’s possible to rank well locally for a search if the product/service keyword is in a category, even if that keyword is not in the LBL title.
The common mistake that our clients for SEO consulting make are to put local keywords in the categories. Examples of local keywords include Michigan, Detroit, Novi, Troy, Southfiled, Oakland County…etc. The most effective way to optimize Google maps is to insert product/service keywords such as piano tuning or used piano. The number of categories is limited to 5 (five). It’s also important to put the most important keyword first in the categories in Local Business Listing (LBL).
Please check other factors of Google maps algorithm for improving Google maps rankings


[...] Keywords in the categories in Local Business Listing [...]