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Be careful about posting articles for the sake of link building. Domain authority matters, but I've seen a lot of people get off track and work towards getting links - when they could be getting links, customers, and industry awareness. Work instead to find your customer and write things that would be useful to them. For example, if you're trying to sell fitness products and supplements, think about where the customer is found online. I'm sure there are lots of fitness blogs. What about getting in touch with them and doing a sponsored giveaway through their blogs? If you're an expert on the topic, you could also get in touch and see if you could contribute regular content about supplements to help their readers understand which ones to use, why, who should use what, etc.