I've been running a number of A/B tests using Google Content Experiments, and have had the same problem across all the tests I've run in the last couple weeks. One variant (the original page) receives about 2.5 times as many visitors as the other.
The pages I'm testing receive about 40,000 visits a week, and I've run single tests for over a week, so it's astronomically unlikely that this imbalance is just a statistical anomaly.
Any ideas on why this imbalance might be occurring?
EDIT: Turns out this is a "feature" (per obscure Google documentation). My question, then, is how can I turn this feature off?