There is probably a disconnect between what you think youhave set up and what you actually set up.
1- Perhaps you are in the control group therefore you do not see the test's changes? (And, why are you putting 96% of your traffic in the experiment instead of 50-50? this seems odd).
2- You didn't say whether the experiment is actually running on the page, only that you set it up to run on that page. Second thing to rule out - the URL targeting may be incorrect - is the experiment actually running on the page?
3- Did you modify the button by injecting CSS or by adding style attributes to the element?
3a- If you injected CSS, the style may be getting overridden by a subsequent or more specific CSS rule
3b- If you altered the element... perhaps the item you are changing does not actually exit when the code is executed but then exists later (e.g., it is added to the page via AJAX after the page initially loads)
3c- If you altered the element... perhaps there is more than one "show more" element and you are updating the first one, but not the one that is visible.
If you share the URL to your product page and give us the ID of the experiment you are expectign to run, we can usually figure out what is not working (but we need to see the page because there are lots of reasons why something may not work).
