Should I use Google Maps API/Geocoding to power a store finder

Question

I'm new to geocoding so I'm not certain this is even the question I should be asking, but all of the other discussions I've seen on this topic (here and on the Google API forum) are so application specific that I feel like I might be missing a very elementary step - I don't need to know how to implement a store finder - I need to know if I should.

Here is my specific situation - I have been contracted to design an application wherein we will build a database of shops (say, independently owned bars and pubs). This list will continually grow and change as shops close and new ones open. The user can enter his/her point of origin (zip code or address) and be shown a list or map containing all the various shops within a given radius in order of proximity.

I know how to deliver these results from a static database: One would store the longitude and latitude as columns for each row and then just use that information to check distances.

But I have inherited an (already fairly large) database of shops which have addresses but not coordinates - so I'm not sure what the best way to get those addresses is. I could write a script to query them one at a time against google geocoding, I could have a data entry person manually look up the coordinates for each one and populate the data that way, or maybe there is a third option I'm not aware of.

Is this the right place to be asking this question? Google Maps Geocoding doesn't host a forum of their own, but refers people to Stack Overflow. Other forums on the net dealing with this topic are all relating to a specific technical question but no one seems to be talking about it from a top-down perspective (ie the big picture).

Google imposes a 2,500 queries per day limit on free users and a 100,000 queries a day limit on paid ones - neither of these seem to be up to the task of a site with even moderate traffic if, every time a user makes a request, the entire database (perhaps thousands of shops) are being checked against Google's data. It seems certain we must store the coords locally but even storing them locally, there will have to be checks against Google in order to plot them on a map. If I had a finite number of locations (if, for example, I had six hardware shops) and I wanted to make a store locator, there would be a wealth of discussions, tutorials, and stack overflow questions available to point the way for me, but I'm dealing with a potentially vast number of records and not sure how to proceed or where to begin.

Any advice would be welcome - Additionally, if this is not the best place to be asking this question, a helpful response would be to indicate a better place to post it. I've searched for three days but haven't found what looks like a good resource for asking such subjective questions.

Answer 1

The best way of course would be when you use a geocoding-service to get coordinates and store the coordinates in your DB. But it's not possible with google's geocoding-service, because it's not permitted to store geocoded data permanent.

There are free services without this restriction, some keywords to search for: mapquest, nominatim, geonames(but these services are less accurate than google)

Another option would be to use a FusionTable. The geocoding would run automatically(but the daily limits are the same as for the geocoding-service). The benefit: the geocoding is permanent(you can't access the locations directly by e.g. downloading the DB-dump), but you may use the coordinates for plotting markers(via a FusionTablesLayer) or filtering(e.g. by distance)

The number of entries shouldn't be an issue, 100k is no problem for a database