What a stupid mistake.Careful of theme updates.
This is just a friendly reminder to be careful of updating your Wordpress Theme. I don't use plugins for a few choice items in my theme because I don't want the additional overhead. This includes header and footer related code.
I made an update to my Theme in mid November and spaced on replacing my Google Analytics code. A few days later I checked in and thought my site was offline. I freaked. I had zero traffic for 5 days.
When you replace your theme you overwrite your header and footer files with new copies. Woops.
Google analytics was a quick fix. Just drop some new code in.
But the real mistake was...
I use Amazon OneLink (if you don't know what it is then look into it here). In simple terms it ensures you capture sales outside of the United States without multiple sites/links.
Talk about a screw up. Right over the Black Friday and Cyber Monday weekends I basically missed capturing every single sale from outside the US Amazon Site because OneLink wasn't configured in my footer.
Let it be a warning...
Use plugins to help you manage your headers and footers...Or have a checklist around to ensure you don't forget such tiny, but every so important, updates.