Thanks for the invite as well Emile, always cool to talk with others about their crowdfunding experiences. We did our first two years ago, and finished a second one in October of this year.
With regards to crowdfunding vs just preorders, there is a lot of hype around crowdfunding sites like IGG and Kickstarter, which leads to people stumbling across your project without the need to directly market towards them. This is a huge benefit, just getting people to take a look at a project isn't easy, and just do to the audience viewing the main crowdfunding sites on a daily basis.
There is also a psychological factor with timed crowdfunding campaigns that I don't completely get, but it's definitely real - for example our last KS campaign the last few days were bringing in around 5K per day. At the end of the campaign we put a big link on the KS page with a link to a preorder page. In about 30 days we've only received about 5K in new order. There is definitely something about being part of the "campaign" and getting in on it, that plays alot into whether someone will back it, vs just preorder a product.
With regards to KS vs IGG, flexible funding is a huge downside that hurts the credibility of IGG. Scams, frauds and inexperienced companies running campaigns is a major issue, and one that hurts everyone running campaigns. IGG has (at least IMHO), been worse at this than KS, so I immediately question the credibility of any IGG campaign more strictly than a KS campaign. That being said, both sites really need to do something about scammers and fraud campaigns from ruining their platforms. I understand why they have a completely hands off approach, however the diminishing credibility of their platforms will negatively impact all projects and their longterm future.
I could talk all day about crowdfunding :), but I have to call it quits right now. Look forward to everyone else's comments.