We also received a similar spam like email and were very confused about what was going on. Initially, they just wanted to make sure a representative of the company could attend the event, because otherwise you're not even eligible to win.
Since then i have emailed them questions, mostly just to find out when the winners will be announced, and have received no responses at all. They seem to keep dragging this out, claiming we're "on a short list to win" but then adding additional rounds of cuts, and now this voting.
It's like all they want is to get more press and publicity for themselves, at the expense of the companies nominated. If I need to be at this thing next week (a Friday and Saturday) I need to plan around it! They can't expect to let me know if I'm a winner, just a few days in advance, and think i will drop everything to speak at their event.
I think it's incredibly unprofessional and very selfish how this is being run.