"More, what disadvantage can we have if we place it right before the body closure trying not to impact the general site's performance?" There are a couple disadvantages. Son mentioned one where you don't have the ability to load certain tags earlier in page load if you need to. The other disadvantage would be that all vendor libraries would have to load at the end of the page load. This would affect how quickly the server calls that send data to your vendors are triggered. This leaves more time for your visitors to navigate away from the page before the server calls are sent, which means there won't be any tracking for that page. Performance shouldn't be an issue. Like Son pointed out, if you're loading the utag.js Asynchronously then the page will continue to load while the Tealium library is loading and pulling in the vendor libraries. Thus Tealium and the vendor libraries will not block or inhibit anything else from loading.
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