What a difference a base coat makes. In the image above, I am wearing Urban Decay alone, without eyeshadow primer. In the image below I started with Prime Time by Bare Minerals and topped it with Decoy by Whip Hand Cosmetics.
The top image is 4 hours after application. The bottom image is 12 hours after application. While it should be noted that not all primers are the same, this illustrates how important prep work really is to the finished eye and longevity of wear.