I placed two "sale time" orders this year both took around a month to arrive ((london). I think patience is definitely the word and they probably get a mass of orders in during their sales, which are fairly frequent, and my last order is still outstanding (placed about 3 weeks back).
As someone also said it's not like I was going to paint them straight away, however....
I think in the current world of 24 hour turnarounds by many companies, customers have certain expectations. BTD could avoid a lot of chasing emails and negaitive comments if they simply said up front, that orders can take up to x weeks. That's not difficult is it ?
Personally given their price and quality I am fine with waiting that little longer, but it's all about customer comms.