DM to the winners? Maybe that doesn’t work 
I guess as long as the proposed signup form is really simple its not a major obstacle. Although I honestly think that will result in non-brain cliking and the same possibility of it being missed on receipt. As a parallel - think of magazine competitions you used to have (maybe they still exist). You smash the form in, but you never check and just assume you’ve lost. The only time you know you’ve won is if the whatever arrives at your home physically. I think I like @matoken.eth’s idea best of making the newsletter (which can announce the winners) a mandatory signup in exchange for entry, because its likely to foster higher readership of it.
I guess it also depends if ENS marketing is part of the goal of the giveaway, which I think it should be, and then whether that’s almost mandatory as a condition of entry, or more organic (less people will share their gift, but the ones that do will be more genuine). I think I prefer the latter, but I’m not strongly opposed.
EDIT: To add, it may also introduce some people to NFTs and how to hold them, where to find a wallet, etc. Which also helps wider adoption of the space and web3.0 in my view. So a further positive, especially if the recipient is new in the space. Everyone has to start somewhere! I got my first NFT in a LinkedIn giveaway in a similar manner.
