app/templates/components/ad-unit.hbs
{{#if (and session.hasUser session.account.isPro)}}
{{! no child element for Pro users at all }}
{{else if isEnabled}}
<div id={{adUnitId}}></div>
{{else}}
{{! @TODO(@Josh): We might want to do something more than text here. }}
<div class="empty-container">
<p>{{t "components.ad-unit"}}</p>
</div>
{{/if}}