Improvement to Link Units
Another recent improvement to AdSense.
We’ve optimized the landing page users reach when they click on a topic in any link unit. By providing users with more relevant ads and topics, we’ve seen improved link unit performance – and you’ll see improved monetization.
They didn’t specifiy what the changes are, but anything that improves performance sounds good to me. I’ll have to try to remember to check the revenue from my link units in a week or two to see if I notice any difference.