Links still matter, and the market for building them is the least regulated corner of search marketing. That combination produces a service category where the deliverable is easy to fake, the metrics used to sell it are supplied by third-party tools rather than by Google, and a meaningful share of what gets sold is explicitly against the rules of the search engine it is meant to influence. None of that makes link building illegitimate. It makes vetting the seller the entire job. This page covers what an agency can genuinely do, which tactics carry real risk to your site, and the specific evidence to ask for before any money changes hands.
What Google's rules actually say about paid links
Google's spam policies name link spam directly: buying or selling links for ranking purposes is a violation, and the policies list the forms it takes, including money or goods exchanged for links, exchanges of services, and articles or advertorials carrying links that are not marked. The remedy Google offers is not secrecy but disclosure: outbound links that are paid for or otherwise commercial should carry the sponsored attribute, and links you cannot vouch for should carry nofollow. Note what that means commercially. A properly attributed paid link passes no ranking value, so the ranking benefit an agency is charging you for exists only if the disclosure is omitted, which is the violation. Any seller whose model depends on undisclosed payment is selling you their risk as well as their placements, and the site that gets demoted is yours.
What legitimate link work looks like
The honest versions of this service all share one property: somebody has a reason to link that does not involve a payment for the link itself. Digital public relations produces research, data or commentary a journalist wants to cover. Genuine partnerships, supplier pages, trade association memberships and event sponsorships produce links as a by-product of a real relationship. Resource and tool building earns links because the thing is useful. Broken link recovery and unlinked brand mention outreach simply collect links you had already earned. This work is slower, less predictable in volume, and impossible to quote as a fixed monthly count, which is precisely why agencies selling guaranteed quantities are rarely doing it. Ask which of these categories each proposed link falls into, and expect a specific answer per placement.
The evidence to demand before you pay
Ask for a sample of ten links the agency built in the last quarter, with live URLs, and open them. Read the surrounding site: does it have an audience, an editor, an about page naming real people, and articles on subjects unrelated to link selling? Check whether the page carries a sponsored disclosure. Ask how the placement was obtained, in one sentence, for each of the ten. Then ask what the agency will not do, because a seller with no exclusions has no standards. Be sceptical of metric-led pitches: domain authority scores are third-party estimates, not Google signals, and a network built to inflate them can look excellent in a tool and be worthless or harmful in practice. Finally, ask what happens if a placement is later removed or the host site is penalised.
Where link building fits in a buying decision
For most local and home services businesses, links are the third priority rather than the first. The profile, the reviews and a site with a real page per service and per area usually produce more movement per dollar, and they carry no policy risk at all. Links matter most when you are competing for genuinely contested national or commercial terms and everything cheaper has already been done. That is why a link programme is normally bought as one component of a broader marketing engagement rather than as a standalone monthly purchase: the agency running your content knows which pages are close enough to the first page for a link to matter, and pointing links at pages that cannot compete on content is money spent on the wrong half of the problem.
Questions people ask about backlink building agency
Can buying backlinks get my site penalised?
Yes. Google's spam policies name buying links for ranking purposes as a violation, and sites that breach the policies may rank lower or not appear in results at all. The risk sits with your domain, not with the agency that sold the placements.
What about guest posts and sponsored articles?
They are fine when the link is attributed. Google asks that links within paid or sponsored content carry the sponsored attribute, which removes the ranking effect. Guest posting at scale, with articles written mainly to place links, is named in the spam policies as a link scheme.
Are domain authority scores a reliable way to judge a link?
No. Those scores come from third-party crawlers estimating link graphs, not from Google. They are useful for rough triage and easy to inflate deliberately. Judge a prospective link by whether the site has real readers and whether a reader following that link would be pleased to arrive.
How many links should an agency deliver per month?
Any agency committing to a fixed number is committing to a process that produces links on demand, which is the process Google polices. Expect a target range with variation, and judge the work on the quality of individual placements rather than the count.