How to get user's current location?

What testing platform will best allow specific targeting of users (such as by location), as well as a "true" 50/50 split in a test (IE - 200 visitors get A, and 200 visitors get B.)?

• Currently it seems that GA's content experiments do not provide 'passive' enough data - that Google tries to sway users to a winning option. We need dead simple, raw A/B testing.

• Answer:

  Optimizely can do this, and it has the Geographic targeting feature you need. So can Visual Website Optimizer I believe, and a host of other platforms. Ideally you want to have a random 50% chance of a person seeing each variation, rather than splitting the traffic sequentially. Google Contents Experiments does this because it uses a Multi-Armed Bandit approach to testing and will give more impressions to the variation it thinks is winning. There are pros and cons of this approach. I usually use straight A/B testing when I do Conversion Optimization.