Anyone who really wants this job can easily get it. The key is research: understand what the company does and make sure you have a thorough knowledge of PPC and you'll be fine.
I applied online and got an email the next day, inviting me to an interview day. As I was not in England at that time, they suggested a Skype interview and they let me choose the date. The interview was about my CV, experiences, uni choices, and specific questions about PPC.
The next day I got an email inviting me to the final stage, which was a presentation at their office in London. They asked me to prepare a PPC campaign for a company and present it to them. To anyone who goes up to this stage, I highly recommend watching the Google AdWords tutorial on Youtube, it will tell you exactly what you need to do in order to design a PPC campaign, even without experience. Once you do this, you'll find the task much easier, don't forget to be creative in your campaign designs, and of course make sure that you are 90% knowledgeable about PPC!
So I presented my campaign in front of two senior ppc employees and they asked me a few other questions about my CV, before discussing the job in more detail. 3 days later they made me an offer. Good luck to anyone going through the recruitment process, but do not worry, they do their best to make you feel comfortable at all times! If you are passionate enough about this job, then you will get it.