By default, dlvr.it automatically appends Google Analytics link tracking tags to all links. This was designed to provide our users with additional reporting / insight into the traffic delivered to their sites via social media.
For example, when adding these tracking tags, dlvr.it appends '?utm_source=dlvr.&utm_medium=twitter' to your link URLs.
For the majority of users, the tracking code adds additional insight & visibility to website analytics reporting.
However, for some users, these tracking tags may result in visitors ending up on an error page on your site.
Here are details: How do I remove Google Analytics Tags From My Links