Greenlight by itself is pretty much useless for gaining an audience or getting new press attention. If you have the option of skipping it and getting onto steam directly, there's no harm done in not having a greenlight campaign.

Most of your organic greenlight audience will appear within the first few days of you submitting your game. If you don't get enough votes during this time, then you're in trouble, because organic traffic disappears. After the first few days, you will need external traffic source (e.g. press coverage, advertising) to drive viewers to the greenlight page.

Steam usually approves a new greenlight batch about once a month. There initially was a very large queue/backlog, but not so much these days. If you've got a decent game (one that can get significant positive votes in it's first few days), you'll usually get approved in the next batch -- so about 2-6 weeks. If you're unlucky you might sit in greenlight hell for a year or more.

In any case, I'd plan to do a PR push at the same time as the greenlight launch, so that hopefully you get some press, which will hopefully drive more traffic to your greenlight page to ensure success. I'd probably engage a game-specific PR consultant to go over your greenlight page itself and review your PR plan before publishing it too.

Most of your organic greenlight audience will appear within the first few days of you submitting your game. If you don't get enough votes during this time, then you're in trouble, because organic traffic disappears. After the first few days, you will need external traffic source (e.g. press coverage, advertising) to drive viewers to the greenlight page.

P.S. there's a lot of very dodgy services out there who promise to get your game through greenlight... Some even call themselves "publishers" and will try to get you to sign contracts where they own a large chunk of your income, when in fact they're just small-time key-giveaway twitter account. Some of these services will actually ruin your chances of ever being greenlit, because if Steam finds out that people have been bribed into upvoting your game in exchange for a chance to win free game keys, they might just ban you outright.

Thank you for your reply. I've heard about the importance of reaching out to bloggers and trying to gain press attention to gather mroe people to the game and keep up the traffic in order to get the necessary upvotes and successfully greenlit the game. Unfortunately I couldn't find a too helpful list about contacts I could reach out to, who would be interested ina small blog post or anything about a kind of more modest nice little game of 3-4 hours of gameplay, but with a lot of beautiful elements and a unique concept. Just randomly trying to find indie gaming blogs and communities using google doesn't really seam to be too effective for me. Anyone got any ideas on that?

I would argue you already need a community by the time you try either getting greenlit on Steam or getting Kickstarted. Just trusting on organic traffic, or shortterm results of a marketing push started with your campaign or shortly before it will be quite a gamble.

How to build such an audience IDK... depends on your game, the time you have for building the audience (you will need to invest into it, a lot), and how far your are into development. A development blog, Youtube and Twitch vids, collaboration with other devs, getting youtubers and twitch streamers to play your game (just beware sending them early builds that make a bad first impression), interacting with interested players from day 1 of going public, setting up ways for interested people to give you development feedback, having a playable demo and lots of marketing material early on all sounds like a good idea.

Make sure you start that early on, like 6 months in advance or more, so your community has time to form and grow. The big splash does not work for a small Indie that neither has the brand recognition of EA, Epic or Ubisoft, nor the marketing budget to shove the ads into peoples faces everywhere. These big players like to keep it secretive (besides some controlled leaks here and there), and then splash the market and sell the game like hotcakes while the hype is still going. You will have to slowly build the hype and hope it can survive for longer.