Hi,
A few things come to mind.
1. As mentioned before I too would focus more on your 'brand', your name or gusty.se and have it more dominant closer to the headline or part of it - 'Learn to kitesurf with Gusty.se' or something. If someone passes the poster and is not be that interested in kitesurfing might remember enough of the poster (a few words) to remember 'gusty.se' and mention it to a friend. That's not going to happen with it in the body copy at the bottom of the page. Think of how recognizable and memorable kite.se is. By making it into a logo (or dominant i a headline) it makes it easier for people to remember.
2. If you can think away the background pattern for a moment, I'd be looking at making the relationship between the items more dynamic (more contrast in sizes). The kiter can be much bigger. It's a great shot and I'd be at least doubling her in size, have her jump out from the page. I don't mind the 'noise' in the background. Sure, by convention the text might be more difficult to read, but anyone who is grabbed by the word 'Kitesurf' and the babe kiting then they are going to read it anyway.
3. Headline. (think about point 1 again) I'd find a way to pump up the size of kitesurf, that's one of the things that will grab peoples attention just because it is a cool new sport, make it bigger. Having the existing headline on one line feels nice and balanced but being on one line tends to force the headline to be a bit small. Maybe have 'Learn to' on one line and the 'Kitesurf' much bigger on the next line.
My 2 cents worth.
Edit: you're giving more airtime to your sponsors then you are yourself