"How are you comparing the CTR being higher with local mode tags vs. something else? "
Local mode shows more impressions AND more clicks. JS shows fewer impressions AND *a lot* fewer clicks. So CTR is higher in local mode.
"Are you doing in-place A/B testing of identical zones on identical pages, and comparing the CTRs?"
Only one Zone in use, invocation the same on all pages. Comparing imps/clicks/ctrs per banner from days/weeks before switching local mode to JS mode.
I just looked at one of my banners. The day I switched from local mode to JS, daily average impressions fell to about 1/3, and clicks went down to almost ZERO. I compared that with other campaigns, banners, it is roughly the same.
While I understand that impressions are lower with JS invoking (as you explained above), I don't get why the clicks are also down? In local mode I have so much more clicks. Clicks should be the same, or not? click is click, after all?