The ranking mechanisms of Google and other search engines are always changing. There are monthly updates that do show visible effects on the ranking of individual websites. While we recommend Youtube traffic for your downloads, search engine optimization is something that does help if your software or webpages are targeted enough. If you're trying to rank for example for 'Best anti-virus' there is billion dollar (decade long established) companies competing with you for the same keyword. You won't win that game. However, ranking for a simple keyword such as 'download free minecraft exploit xyz' is easy. Let's focus on that.
Google and other search engines rank website based on importance. If a website seems to have a lot of quality backlinks, it seems to the search engine that it is an important website. The algorithms might looks at a thousand different things to rank each website. This seems to be the most important one though. In the past there were bots that created (junk) backlinks to achieve this. That does not work any more. We recommend the legit route to avoid any blacklists. The legit route is basically having quality content and getting real backlinks of users that like your website. Forum posts do count as backlinks in some cases. Besides the fact that they actually might take real users to your website through the link, the added benefit is reputation creation with search engines and thus a higher rank. The added benefit of these backlinks is quicker page indexing. Once a page is created, it isn't immediately indexed. If there is not a single link from any page to your page, there is no way for Google to know about your page.
A page without proper content and without the necessary length won't get highly ranked as a new site. Enough lenghty content is a must. About 500 selfwritten (or on-copied) words should be sufficient. While the content should be easily readable (e.g. no small text on mobile screen) there are other factors that you should take into account as well. The overall layout of a website has a huge impact on the user. If users immediately get repelled by the layout, it gets counted as a 'bounce'. A user that immediately leaves. This lowers the quality of your website in the sight of search engines. A user clicks on the keywords, and immediately went back says enough right? Besides making money, Google also wants to serve the right website to the right user. You may think for yourself and come to the conclusion that once users bounce off the website, Google knows they did something wrong. This is not confirmed by anyone obviously, but clear sense will get you to this conclusion. Make sure your content is unique and not copied. If your content is partly copied from another website is not original content any more, so that is deemed unimportant for obvious reasons.