Links need a worthwhile destination
Before acquiring links, make sure the target page answers a real search need and deserves to rank. A weak destination does not become useful because more links point to it.
Technical foundations matter
Canonical errors, noindex tags, crawl blocks, redirect chains, and broken internal links can undermine a link campaign. Fix those before treating authority as the bottleneck.
Internal links distribute attention
Use topic hubs, contextual links, breadcrumbs, and sensible navigation to connect externally linked pages with related pages that matter.
External links vary in value
Relevance, source quality, page context, editorial independence, traffic, and the reason the link exists all affect how you should value a placement.
Avoid single-factor thinking
Rankings can change because of content, competitors, algorithm updates, intent shifts, technical changes, or links. Evaluate link building as part of the system.
Important policy context
Google's current spam policies identify buying or selling links for ranking purposes as link spam. Google also says paid advertising or sponsorship links can be legitimate when appropriately qualified with rel="nofollow" or rel="sponsored". Read Google's spam policies.