Interfaces should be compelling, and generally, intuitive.
I just saw an example of how not to do it – http://www.hasrimy.com/ – I draw your attention to the top right corner of the screen.
If you have to have something to explain a fundamental part of your interface – “scroll right for more” – it sort of says something about your interface. In particular it says, “I tried to be different but I’m so different, I have to tell you how to use me.”
It doesn’t, as a result, say “I’m easy to use.” and definitely doesn’t say, “I’m innovative.”