How Flash-Sale Offers Work
A flash-sale offer is a special discount that we launch for a limited time only.
We use to manage 2 differnt types of flash-sale offers:
offer type #1: 15-day trial + 50% Off the first month; and
offer type #2: 20% lifetime discount.
Offer Type #1
The kind of offer will work only if you are still eligible for trial. Otherwise, you can grab neither: the 15-day trial, nor the 50% off.
Additionally, you can grab that offer only if it is not already applied to any invoice yet. Otherwise, you will see an error message like the one show in the picture below.
Offer Type #2
Unlike Offer Type #1, all you are always eligible for the Offer Type #2 (lifetime discounts)
You can grab this offer as many times as they want, while it is available.
Additionally, the Offer Type #2 will provide a 15-day trial if you are eligible for it.
Next reading: How Add-Ons Work.