Hey crew,
Just jumping in to give some clarity here.
The Lethal Tides DLC was originally planned to be used as a way to trial supporting Streamers who play Hell Let Loose. Currently that's ongoing with a small group of Twitch Broadcasters where gifting a subscription to their channel whilst they play HLL will award the DLC key.
Now it's also important that whilst doing that we have parity with our home platform on Steam, hence it being on sale on there too. This gives those who don't use Twitch the opportunity to also purchase the DLC and access the content.
So in a nutshell:
Get the DLC from a selected Streamer playing HLL: Support the streamer directly as they share Hell Let Loose with their audience.
Purchase from Steam: Standard purchase, sales go to Black Matter / Steam.
With this particular DLC we're really keen to support the Streamers who have helped support us, so if you do have a choice we think that'd be a cool thing to do!
Naturally it's totally up to you.
It's also worth mentioning that this is the first time we've ever done something like this, so feedback is always welcome. Also if you'd like to be considered for these kinds of things in the future - my door is always open.