Hi Mike,
I can see you are going for a clean slick "web 2.0" sort of feel. The site is definitely neat and I like the simplicity, but it just doesn't grab me the way a marketing site should. It's a bit bland.
I think you need to take the message from the last line of text on your front page:
"We recognise the ability of design to stimulate the senses."
...and apply it with gusto!
Looking at some of your competitors:
http://www.connectingimages.com.au these guys grabbed me. I have no idea what the ball of wool is about, but the colours got me interested, and the typography is interesting.
These guys:
http://www.marketforce.com.au/ also got me in with the animation.
.. and both these competitors lead with cool tag lines:
"Small enough to imagine possibilities, big enough to deliver them" and "Intelligent, imaginative, energetic", while you guys lead with "Engage Marketing is a marketing & design consultancy business based in Melbourne." I know it's good
SEO but it's a bit boring.
I hope you find this constructive. Like I said, I like the site, it looks good.