It's all very simple, instead: the email announced TWO things:
1) The EUR has going down recently, mainly because of economic problems in Greece, which forced all the EU countries to a very expensive financial rescue, that had an impact on the EUR value. To reflect this, we have adjusted (lowered) our prices in US$ (and other non-EU currencies) to better reflect the current EUR value.
Since we are payed in US$ by Esellerate, and those US$ (for us) are now worth more than they used to be, we might have *pocketed* the difference. Instead, we chose to pass the saving to our customers, by lowering all our list prices. This means, to everyone paying in currencies other than the EUR, our products are now cheaper.
This concluded the first part of the announcement.
2) We are having a sale THIS WEEKEND, which of course doesn't have anything to do with the fact the EUR has gone down, and we would have had it anyway, but it might have been interesting for non-EU customers to know that, the combination of having lower list prices AND having a sale (this weekend) would result in significant savings.
Of course, EU users would benefit only by #2...
About Labour Day: it's begin celebrated on May 1st basically everywhere in the world, except US/Canada. However, that doesn't obviously mean US user can't get the offer! Last offer we made was on Thanksgiving, which is not an holiday in Europe, but of course everyone had access to the offer.
Using an holiday it's just a way to give some significance to the event. We might decide one day to make a sale on my birthday instead, it wouldn't make much difference...
