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.
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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.