Missing activated Features
In some salesforce.com editions features are not available or need to be activated by salesforce. Please ensure, that your organization meets the requirements.
Salesforce.com Release Updates
Salesforce releases at certain intervals new versions called “Spring”, “Summer”, “Fall” or “Winter”. While salesforce is updating all editions and organizations, it is not possible to install new packages because editions and packages are not in sync. In this case you should try the installation a few days later.
The package ADvendio requires third-party access to communicate via API with the ad server. That behaviour is normal.