Link building is the part of search work where the gap between what agencies sell and what search engines permit is widest. Links still matter, which is why the market exists, and the fastest way to acquire them is the way that Google's own documentation describes as spam, which is why so many campaigns produce a temporary rise and then a problem. A buyer does not need to become an expert in link evaluation, but does need to know which categories of campaign are safe to fund, which are being quietly bought on their behalf, and what a credible plan looks like when it is written down.
What Google's policies actually say
Google's spam policies define link spam to include buying or selling links for ranking purposes, excessive link exchanges, large-scale guest posting campaigns with keyword-rich anchor text, automated link creation, and requiring a link as a condition of a contract without qualifying it. Payment in this context is not only money: free products, services or anything of value in exchange for a link falls in scope, and the remedy where a link is commercial is to qualify it with the appropriate attribute rather than to hope. The 2024 core update announcement extended the thinking further by naming site reputation abuse, where third-party content is published on a reputable site largely to exploit its ranking signals. Read those two documents before you buy anything, because most of what is sold as link building in this market sits somewhere inside them.
The campaign types that are actually defensible
Four hold up. Digital PR, meaning original research, data or a genuinely newsworthy story pitched to journalists who cover the subject, which produces links as a side effect of coverage rather than as the purchase. Resource and citation work, meaning getting listed where your business genuinely belongs, such as trade bodies, supplier directories, local institutions and partner sites. Reclamation, meaning finding places you are already mentioned without a link, or links pointing to broken or redirected pages, and fixing them, which is unglamorous and reliably the highest yield per hour on most established sites. And building something worth linking to: a tool, a dataset, a definitive reference that other people cite because it is useful. None of these can be promised as a monthly quantity, which is precisely why agencies that sell by quantity are not selling these.
How to buy the work
Insist on the acquisition method for every link, in writing, in the monthly report: which page, which site, how it was obtained, and whether anything of value changed hands. That single requirement removes most of the risk, because an agency buying links will not want to document it and one earning them is proud to. Refuse guaranteed volumes, since nobody controls an editor's decision. Ask what the agency would do if a client insisted on a target it considered unsafe, and listen for whether they have ever refused. Ask how they choose targets, and prefer relevance and genuine audience over any third-party authority score, which is a vendor's model rather than a search engine's. Buyers comparing link building agencies should weight this documentation requirement above price, because a cleanup is more expensive than the campaign that caused it.
Measuring it without fooling yourself
Link counts are an activity metric and easy to inflate. Better instruments: movement on the specific pages the campaign is meant to support, whether the linking pages have real readers, and whether referral traffic exists at all, since a link on a page nobody visits is a signal at best. Track the ratio of earned coverage to placed content, because a programme drifting toward placements is drifting toward the policies above. Keep a full record of every link acquired on your behalf, with dates and methods, so that if the engagement ends or a problem appears later, you can audit it rather than reconstruct it. Most sites that need a disavow exercise need it because nobody kept that record while the campaign was running.
Questions people ask about link building campaigns
Are paid guest posts risky?
Yes, when the link is the product. Google's spam policies specifically name large-scale article campaigns with keyword-rich anchor text posted on other sites for ranking purposes. Contributing genuinely useful writing to a publication your audience reads is different, and the distinction usually shows in whether anyone would read the piece.
How many links should a campaign produce?
There is no honest monthly number, which is the point. Earned coverage arrives unevenly because editors decide it. Judge a programme on the quality and relevance of what it earns and on whether the supported pages move, and treat any guaranteed quantity as a description of how the links will be obtained.
Do third-party authority scores matter?
They are useful for triage and nothing more. They are vendor models built from crawled link data, not signals a search engine uses, and they are trivially inflated. A relevant link from a modest industry site with real readers is worth more than a high-scoring link from a site with no connection to your market.
What if we already bought bad links?
Start with an inventory: every link you can identify, its source and how it was acquired. Remove what you can, qualify what you control, and consider a disavow only for clear, large-scale paid patterns. Then fix the underlying reason the links were bought, which is usually a content set that nobody would cite.