I am planning to purchase guest posts at Kallisto.io. But my friend told me that many authority sites don't welcome guest posting. So, the chances of me getting quality backlinks from high authority sites are slim. His advice to me is to buy niche edits instead because it gives immediate results and the chance of getting traffic is higher because the links were inserted within the already indexed post or page. I'm am not an expert on link-building strategies but should I follow my friend's advice? Or should I stick with guest posting?