Brand-measurement on the Internet

A recent study released by the Online Publishers Association and comScore has shown that display ads produce a 50% lift in Internet searches for brand terms within a week of viewing. But without an immediate click-through, that's not easily measured.
So the big question that arises is:
Is online advertising more similar to offline advertising than we perceive it to be? Is CTR the right way to measure effectiveness of an online ad? Do we need to adopt traditional measurement tools for adgudging effectiveness of an online ad?