Disclaimer: I used to work for a crowdfunding platform.
Fees vary pretty wildly. The platform fee is typically around 5%, but what you don't see is the payment processing fee - anywhere between 1% and 3.4% + 20p for every transaction. This can make a huge difference. If you've got a £1000 project, the fees you'd pay are:
5%= £50 to the platform
1% processing fee = £10
3.4% fee + 20p = £23.40 if everyone pays £10 each, £43.40 if everyone pays £5.
So you're talking about losing iro 8-10% to fees and processing.
Indiegogo is best for arty stuff, Kickstarter has that overall reach and audience, but that's as much a problem as a blessing - you're competing against a lot of other projects, so discovery is a problem.
Niche platforms like Spacehive for civic stuff, or Seedrs for company things are good.
https://hubbub.net/ are nice guys and will help a lot (not who I worked for).
It's worth bearing in mind, even if it seems obvious - a lot of people act like crowdfunding will be magical money from the sky. It isn't - have your friends and family lined up to do early donations on day one when it goes live, and regular (but not spammy) updates will be useful - a lot of people will scroll past it on their phone, say 'oh yeah, I'll give ten quid to that' and then forget it - the gentle reminders are best. Likewise, get those friends and family from day one to email other people that might be interested. Videos are often crucial (I never watch them, but i'm in the 4-8% of people who don't - most people do.) - keep it under 2 minutes, pretty factual and upbeat.
Feel free to ask any questions or PM me if you want.
