So, I was thinking: what if users sent in postcards of their hometown and/or pictures of themselves (optionally with LJ clothing?) and/or their LJ username, and we plaster the walls with them?
It'd be totally cool for both us and visitors, and it'd give us a constant reminder about who we're working for.
As an incentive for sending one in, we'd put up a "Danga Virtual Office Tour" page where people could navigate around the office, looking at the walls, looking at all the postcards/pics, including their own. We'd sort them by state/country, so as you walk around the office, you'd move through geographic regions.
We considered other incentives, but the root problem is we don't have enough time to enter in everybody's info if we were to give out invite codes or whatnot.
But the problem of doing no incentive (besides space on the wall) is that if we switch to an incentive system later (with barcodes and a barcode reader?), then the early people might want incentives retroactively?
The previous website I started required a postcard to create an account (and I entered them all by hand, fighting to read the sloppy/rain-soaked writing), and I was getting hundreds of postcards a day for a while.
I think this would be totally cool.
Update: I figured out how we'll do incentives: every day we'll pick a random postcard or so (depending on volume) and give a free 2 month paid account away. We'll then mark the back of the postcard with highlighter or something so we know it's already been a winner, and we'll also keep track of winners on the computer, so people flooding us with postcards with the intent to win won't win more than once (though they might increase their odds). This way we limit our work to a minimum, and it's still mostly a postcard-for-nothing scheme, but there's a hint of chance/fun/lottery going on too.