FOSS4G 2013 Lessons Learned
This year we had a "supporter" sponsorship level, which was aimed at those companies who would not want a stand, but would want some minor branding on the website and at the event. This was very popular and we'd recommend it to future organisers.
A submission notification should be provided within the service for submitting abstract, workshop, etc. An automatic reply mail would do the trick. We did have a section on the web page leading to the submission section that said people wouldn't receive confirmation, but either they missed this or wanted to check anyway, so it ended up causing more work.
We've used Lanyrd to publicise the event alongside the "usual" channels, and also Eventbrite for dealing with the free hackathon registration.