Problems adding remarketing code to one site in multisite

I need to add remarketing code to just one site in a multisite setup. I've done this before, but it's not working this time. To test, I added this code to print out low in the footer:
<?php global $blog_id; ?>
<?php if ($blog_id == 41) : ?>
<p>Statement prints here.</p>
<?php endif; ?>
That's not working either, so I must be missing something. Any ideas?