I experienced with that in the past and I do believe that I did get results.
Sales periods in shops do work.
The side effect is that over time, people tend to slow down their shopping behaviors outside of these sale periods.
It gives a serious "Marketing" and promotional touch to my site and offers.
I noticed in the past, that promotional energy is something I need to use with caution.
One word of advice: don't speak to people as if they were stupid!
First it is a stupid thing to do!
Second it's not a nice thing to do!
Third, it hurst your business and credibility!
Think about that.
Yes! You can create urgency but use it VERY carefully!
Limited time offer... Every time I see one, I KNOW that I am being manipulated.
It almost stops me instantly from wanting to go further.