What does it tell you?
Obviously it tells you that you're doing better this year than last year at getting traffic to your site but what do you think is going to happen when you send this to your boss or present it to the marketing or merchandising teams?
Someone will invariable ask what happened in January and June this year? Undoubtedly, being the analytical Schwarzenegger you are you've already done your due diligence and looked into this prior to the meeting. You immediately reply with "January we had some inventory issues so we pulled our banner ads for that month and June we stepped up the Father's day advertising and had some online only deals".
In my opinion a graph like this should tell a story of what happened and answer more questions than it raises. Why not add some insight to the graph like so...
By taking a few minutes to figure out what caused the dips and spikes in the graph you are providing insight. Plus, instead of spending 15 minutes of the meeting with people asking what happened here and there you save the speculation and guessing and provided a detailed account of what occurred and the impact it had.
