I have been researching the numerous Over Query Limit error messages people have been getting recently. Google has made some changes recently that have made quite an impact on how the geocoding process works. I have documented some of the findings as well as links to relevant pages at Google on my site:
1) Geocoding is now ONLY available via v3 of the Google API system.
2) The Google Maps V3 API key is IRRELEVANT on geocoding requests. The API key is only passed on the user search when looking up the address/zip the user enters. For geocoding locations it is not used.
3) The limit on geocode queries is 2500 requests PER IP ADDRESS. This is important. Are you on a shared server? Using Amazon cloud or other virtual servers? Any server without an IP address dedicated solely to your WordPress site will be sharing an IP address and thus sharing Google API calls.
What about Google API keys increasing limits? It is possible but you must have a Google Maps API for Business account. This is NOT the free account or free API key you can get on their site. You must SIGN UP and BE APPROVED by Google. It is NOT an instant process. You will be assigned a sales rep that will deem you worthy (or not) and sell you the service.
You start by clicking this link and going to "contact us" for Google:
If you are deemed worthy you will be given a client ID and a unique application signature.
I am still waiting for my approval from Google for a client ID & signature so I can build the code-signing service into the Pro Pack add-on in a future release (3.8.???, assuming I'm approved by Google).
What are your options if you are not approved? Few. You can either hope to get your locations geocoded by trying time & time again after a 24-hour wait -OR- you can rent a web server for your WordPress site that gives you your own dedicated IP address. If you are not paying $100/month OR MORE you are highly likely to be on a shared server, virtual shared server, cloud server, or other service WITHOUT a dedicated IP address.
IMO if you are encoding THAT many locations you probably should be on a dedicated server anyway. If you are not aware of the significant security implications of being on a shared or virtual server, you should be... unless all the stuff you are putting into your WordPress site isn't all that important.
So bottom line, if you are seeing "OVER QUERY LIMIT" messages when loading locations you need to rent a dedicated server or get the "Google Blessing" to be approved as an enterprise class business and then wait for the SLP update that supports the new client IDs + signatures for the Google Maps API for Business setup.