Most segmentation strategies focus on things like gender, geographic location, race, weekend vs. weekday traffic and the like. However, I have found that segmenting by user action is far more effective at driving conversion.
If you're going to offer the customer a reward of some type, consider re-framing that offer in another way and see which one converts at a higher rate.
Testing for testing's sake is all well and good, but to really understand your customer you should have a strategic plan and calendar that creates long lasting lessons you can draw on.