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It's not uncommon to take more aggressive and less "natural" link building tactics for a site that is relying on self-funding or needs early growth. I've seen sites start out with unnatural links then safely transition to a "natural" link profile with high value links from key publications later to develop stability. This approach can work to drive short-term success with avoiding the potential long-term issues.

Don't worry too much about DA of the site's you're getting links from. A natural link profile is a mixture of volume and quality. A natural link profile for a new site should include directories, forum links, guest posts, social links. Although these types of links are not important for an established site, it's important for a new site. But online PR on hyper contextual content is the most important factor, even if the site has a low DA but it highly contextual, you should go after those links. Focus on contextual online PR.