You can use the Library Search to find case studies on successful campaigns. Below is what a sample search strategy looks like in the Advanced Search form. To view it live, click here. Log into your Library Account and you can save this search strategy ("Save Query'). You can also pin relevant articles to your account.
Search Google News. I would search the platform and a phrase such as marketing campaign, for example:
Youtube successful marketing campaign
If there is an article that is not fulltext, return to the Library Search to see if it is in one of our databases. If not, we can access it via Interlibrary Loan.