For my first flying gig I went around the country (New Zealand - both Islands) knocking on doors, and eventually was accept into an aero club on a casual basis. I went and asked at every place that might have a flying connection, and whilst alot of people said no, they all said that they were glad to see that I was proactively searching, meeting people rather than sitting at home sending heaps of emails.
After my first job ended (redundancy) I saved up and moved to Australia as I had seen jobs that I wanted to apply for. Just after I arrived there was another job advertised that I applied for on a Friday afternoon via email, received a phonecall Monday morning requesting a job interview and flight Tuesday. I started a week later, approx 1 month after arriving in Aus.
From my limited experience I can say it depends on the company, and how it is set up. Some places only will hire if you knock on their door at the right time, others will only accept emailed CVs, so I cannot stress this enough: If reply to an advert READ and FOLLOW all directions/requirements.