the 35 domains that link to every major project management tool

a backlink gap analysis sounds abstract until you run it on real data. so we did. we pulled the highest-authority referring domains for the eight biggest project management tools straight from the common crawl webgraph, then looked at the overlap. the result is a near-perfect illustration of why link building works the way it does, and where the actual opportunities hide.

how we pulled this

we took eight tools: notion, trello, airtable, asana, monday, clickup, basecamp, and linear. for each one we pulled its top 2,000 referring domains ranked by cg_authority from the common crawl webgraph (about 120 million domains, 4.4 billion links), then intersected the eight lists to see how many tools each linking domain points to. no proprietary index, no scraping, just open data anyone can query.

first, the headline numbers for each tool. note the spread: trello and notion have roughly 50,000+ referring domains, while linear, the newcomer, has under 2,400.

backlink overlap is a pyramid

across the eight samples there were 9,347 unique linking domains. here is how many of the eight tools each one links to:

about 69 percent of the linking domains link to only one of the eight tools. those are noise for outreach: a site that mentioned trello once in a listicle is not going to link to your new tool because you asked. the value is in the thin top of the pyramid. only 39 domains link to all eight, and only 0.4 percent of the whole set links to five or more.

the 35 domains that link to all eight

here is the thin top of the pyramid, the domains that link to every one of the eight tools, sorted by authority. if you launched a project management tool tomorrow, this is the outreach list you would start with, before you wrote a single blog post.

domains linking to ALL 8 tools, by cg authority (top of the list):

github.com          81     substack.com        75
hubspot.com         70     gitlab.com          70
zendesk.com         69     atlassian.com       68
zapier.com          67     entrepreneur.com    66
habr.com            65     buzzsprout.com      62
dev.to              62     ycombinator.com     61
userpilot.com       61     libsyn.com          59
kit.com             58     beehiiv.com         58
n8n.io              57     luma.com            57
smallbiztrends.com  57     zenn.dev            57
hatenablog.com      56     logrocket.com       56
canny.io            55     ghost.io            53
coda.io             53     stackshare.io       53
taskade.com         52     lovable.dev         51

35 domains link to all eight. these are the highest-authority ones.

the most striking part is how clean it is. among the 959 domains that link to four or more of the tools, only 2 percent are platform or cdn noise (the googles, wikipedias, and amazonaws of the world). ninety-eight percent are real, editorial, on-topic domains. the overlap method does the noise filtering for you, almost for free.

what the category linkers tell you

read the all-eight list closely and the niche's actual link-building playbook falls out of it. the universal linkers cluster into five buckets:

integration and automation hubs (zapier, atlassian, n8n, stackshare). every serious tool gets listed where integrations live. these links are earned by building the integration, not by pitching. developer and product communities (github, gitlab, dev.to, ycombinator, zenn.dev, habr). tools that ship in public get linked by the communities their users live in. publishing and creator platforms (substack, beehiiv, ghost, kit, buzzsprout, libsyn). newsletters and podcasts about productivity cite the tools they run on. support and feedback infrastructure (zendesk, canny, userpilot, featurebase). and adjacent and comparison tools (coda, taskade, lovable, uxpin, logrocket) that cross-reference each other.

that is a real strategy, not a guess. if those five buckets are where the category's links come from, that is where a newcomer should spend its first hundred hours, in that rough order of effort-to-reward.

the newcomer proof: linear

linear has 2,352 referring domains. notion has 52,330, more than twenty times as many. and yet linear still shows up linked-to by the category linkers, sitting on the same all-eight list as notion. that is the encouraging part for anyone small: you do not need fifty thousand backlinks to compete, you need the few hundred that your whole category already links to. the gap between you and the incumbents is a short, specific list, not an ocean.

how to do this for your own niche

nothing about this is specific to project management. pick your two or three closest competitors, pull their referring domains, and keep the ones that link to several of them but not to you. sort by how many competitors each links to, then by authority. the top of that list is your warm outreach sheet, pre-filtered to the domains that link to your category for a living.

that is exactly what a backlink gap analysis does, and you can run it free on the same common crawl data we used for this study: enter your domain plus a few competitors and you get the ranked, noise-filtered overlap in a few seconds. the free tier shows your top gaps; the lifetime plan unlocks the full list, csv export, and an api if you want to script it across a whole portfolio.