There has obviously been a wide variety of things given away, and I recall different time frames having been used depending on the item -- which is I think totally appropriate. Especially if the goal is to build excitement and encourage participation. In general, high-value items should have longer entry periods because 1) more people get a chance to enter and 2) the anticipation builds over time when you're thinking about winning an Elzetta, for instance. I can't recall how long the Elzetta entry period was, but I want to say it was like 10 - 14 days or something, which seems about right, and is probably as long as I'd want to go unless we're giving away cars or something
The E99 Ti is I think just right at 4-5 days to submit entries.
For smaller items, I think it's cool to just give it away to the first person who wants it, but in general I think there should be at least 8 hours for people to enter.
Just my opinion.
And thanks again for starting and growing this thread Doc!