My wife is one of the smartest people I know. However, she is not the most technologically sophisticated person (not a blogger, does not use RSS) and is not a marketing person either (she's an academic). So, when she told me that she never clicked on URLs in organic search results that were "really long or complicated" I thought she was crazy. I mean if you only clicked on the shorter URLs, you miss out on all these other great results that are deep links into a website and probably have just what you are looking for.
Well... now we have DATA (every marketers best friend) to prove that in fact, my wife is right. Again. (I have not been married too long, so I have not learned this lesson thoroughly yet.)
In any event, a new report from our friends at Marketing Sherpa shows that longer URLs in organic search results receive fewer clicks than short URLs. Here is a heatmap image showing the difference.
Two things to notice:
1) The eyetracking activity is actually pretty similar between the long and short URL listings, so they are both getting a lot of attention.
2) But the clicks (the good stuff!) were more focused on the listing with the shorter URL.
Takeaway: All things being equal, you want a short URL. So keep those keywords in the URL short, and try to eliminate anything unnecessary.