Updated: import limitations. As of June 11, 2018 those geocoding limits will change. You will have a pay as you go billing requirement. You will need to reconsider how to import, how often to import , and whether to break the list into smaller chunks , or skip geocoding, or switch to the MYSLP SaaS managed service and choose the Professional or Enterprise level plan (some restrictions apply) .
In order to perform bulk location imports with a CSV file for the WPSLP plugin you will need the Power add-on installed. WPSLP Power add-on does not alleviate the need for you to obtain your own API key. MySLP users do not need to obtain their own API keys but will need the Professional level plan or higher to import and may have limitations according to the plans.