I applied online. The process took 1 day. I interviewed at Voxpark (Berlin) in Oct 2014
Interview
Not really an interview, as they more or less accept anyone if their English skills are up to par. You will get signed up for a two week contract and if you manage to get about 13 sales within the 2 weeks they will offer you a longer term contract.
You will be expected to make calls on the first day, after they have presented you what you are trying to sell.
Interview questions [1]
Question 1
You have to introduce yourself to a group of people. But there aren't any really tough questions.