I've bought a Skype Number in Ireland, and instead of a number with area code, I chose the VoIP option (076 area).
My number was not receiving calls from many users, from different countries, and after having a chat with Skype Support, I was told that VoIP numbers can be blocked by some operators.
The whole process of canceling the VoIP number and getting a new one was dealt perfectly, but we noticed that there is no disclaimer or warning in the purchasing page about the possible limitations of a VoIP skype number in Ireland.
So my suggestion is to make a very clear warning on the purchase page, or stop selling this option if it's not able to deliver the same as the other products.