Latest news from the u2.com Zoo Mods twitter account:
PRESALE CODE EMAIL INFO: eXperience going out in next couple hours iNNOCENCE GOING OUT TOMORROW - That is all , Baja 4:30 PM PST
That was posted 23 min. ago, check https://twitter.com/U2comZooMods
Regular sale? lol! Last tour, the tickets were sold in half an hour in France
8 minutes in Holland for the Amsterdam Arena (50.00 people) , now the ZiggoDome in Amsterdam , only 15000 people, so I'll think about 3 minutes ?
The limit for presale is 2, the limit for the general sale is 4. But if you try and buy a set in the presale and another set in the general sale with the same credit card, they cancel all your tickets without notice.
Only when you exceed the total of 4, so you can buy 2 in pre-sale and 2 for the same show in regular sale.