Where YouTube lets you put links
Three slots matter: the description of each video (the first lines show before the "more" fold), your channel links which appear on your page and near your banner, and the channel about text. Those are all places a viewer can click.
The problem: if you paste five different URLs into each slot, you spend your life updating them and your stats end up scattered across nothing. One sponsor link changes and suddenly you are editing dozens of descriptions by hand.

