In the following video, Jeremy Phillips and Austin Smith discuss Facebook.

Austin says Facebook's having trouble monetizing its user base. Increasing ads drives many users away, and still others are turning to mobile, which is even harder to monetize.

As for Web stocks that can be successful in online advertising, Austin points to Google, with its wide moat, the success of Chrome and Android, and its control of search engine optimization and search algorithms around the Web.

For more details, check out the video.

Austin Smith and Jeremy Phillips own shares of Google. The Motley Fool recommends and owns shares of Facebook and Google. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.