If your goal is geo-redirection then a 3rd party service is usually a bad choice (speed + downtime). An memory geo-ip database is the best way to go - but this is usually also part of what you pay for when you buy the non-free version
It's less accurate than their commercial offering, but good enough in many cases. For ease of use, there's a nice C API (https://github.com/maxmind/geoip-api-c) and wrappers like pygeoip for Python.
