My thoughts:<p>1. I opened the web site and said ah, this looks pretty cool, I installed the software and thought, eah.. okay I'll install it even though I really don't want to install anything.<p>2. Upload was simple after signup.. I understand you have to do the signup thing to validate people somehow.. so for my test I sent a small file to myself..<p>3. Got the email to download it saw the link and tough ah sweet, just click it.. and was presented with the exe download.. hmm another thing to install to download the file... I thought, nah, not worth it, I don't want this thing anymore, form there I deleted the client.<p>You need to make it simple to share with people who don't have the downloader, you can't expect people to install something to download files they were sent.<p>Keep it free yet cap files to say 1MB for free users or something simple.. Paid users ~$5/mo get 2GB uploads..