Duplicate Optimizely snippet
I have anOptimizely snippet implemented in the source code of one of my web pages, and it's also implemented via Google Tag Manager on the page. Will this impact my experiment and tracking?
Pretty sure this will cause variation code to execute twice.
In some cases, this would be fine... if you replace "BIG" with "small", when it runs a second time, there are no more "BIG" so the second pass through would actually do nothing. or if something was detached and moved to a new location, it can get detached again and reattached right back at the same location again.
but... if you have something that replaces the "<h1>" with an "<h1> and a paragraph"... when it runs a second time, you will now have one <h1> and 2 copies of your paragraph of text. Or if you are moving the 3rd item in a list to the 1st position in the same list, when it runs a second time it would be moving the "new 3rd item" instead of the one you really want.
Analytics and Testing Guru