Google still doesn't release the profit figures for youtube, only revenue. Even the revenue figure was a secret until 2--3 years ago, so it was probably not that high. If youtube was very profitable, I'm not sure why Google would hide it in its earnings since they almost always try to show how they aren't exclusively dependent on their search ad business. I'm not saying youtube does not make any profit at this point, but if it wasn't tiny there's no reason for them not to talk about it.
I mean, the opposite is also true, isn't it? If Google's search ad revenue was going down while YouTube ad revenue was going up, I feel like Google would want to keep that a secret so that people don't realize that search ads are shrinking in relevance.
Basically, I don't see that Google has any incentive to break out its profits by line of business unless someone forces them to. They're better off if you just look at a black box of ad revenue and say "yeah it's all profitable, so ads are as strong as ever."
