What is inbound marketing?
Inbound is when the leads come to you. Someone has a problem, they search for it, ask ChatGPT about it, ask a mate, read something you wrote, find your website, and get in touch. Search engine optimisation, useful content, referrals, reviews, your Google Business Profile and the emails you send to people who asked for them are all inbound. The cheapest version of it is organic content: writing the answer to a question your customers keep asking, and putting it where they'll find it.
What is outbound marketing?
Outbound is when you go out and get the leads. Cold calling, cold email, LinkedIn messages, knocking on doors, turning up at the trade show and working the room. You pick who you want and you start the conversation. The cheapest version is a phone and a screened list. Easy and simple as that.
One thing to know before you read any comparison, including this one: the term "inbound marketing" was coined by HubSpot, who sell inbound software, and the loudest voices for outbound are companies that sell contact data and diallers. Every page on this subject is written by someone with a horse in the race. Mine's retired.
The stat everyone quotes is from 2011
"Inbound leads cost 62% less than outbound leads." You'll find it on half the pages that rank for this question, sometimes as 61%, sometimes 60%, depending on which year's version got copied. It's a real number from a real source: HubSpot's State of Inbound surveys in 2011 and 2012, in which around 650 marketing professionals estimated their own cost per lead. Firms that spent most of their budget on inbound reported £143-ish per lead against £373-ish for outbound-heavy firms (in dollars, but you get the idea).
Five things wrong with using it today. It's fifteen years old, from before paid social, AI search, GDPR and the cookie changes. It was self-reported, not audited. It's observational: the businesses that chose inbound were different businesses. The publisher sells inbound. And it measures cost per lead, not cost per customer, which is the only number that pays your mortgage. No independent comparison exists for UK small B2B firms in either direction. I looked.
Here's the honest cost picture for a firm with under twenty staff: the biggest cost of both is your labour. Your calls are only "free" if your time is worth nothing, and your blog posts are only "cheap" if the evenings you spend writing them don't count. They count.
The real difference is speed versus compounding
Strip out the vendor maths and one difference survives. Outbound is fast and stops when you stop. Inbound is slow and keeps going.
A compliant call to a screened list can produce a conversation the same morning you start. It can also produce nothing the day you put the phone down, because nothing about it accumulates. Inbound is the opposite. Ahrefs studied how long pages take to rank in Google and found that only 5.7% of pages reached the top ten within a year for even one keyword. Their own warning about the "two to six months" figure you'll have read: "this data only represents the 5.7% of pages that were lucky enough to rank in the Top10 within a year, while almost 95% of all the pages we studied didn't make it." That study is from 2017, and nothing has got quicker since.
The vendor timelines of three to six months assume a team doing it full-time. For an owner doing it in stolen hours, six to twelve months to meaningful inbound enquiries is closer to the truth. And then it keeps paying. The page you wrote last spring is still answering the phone for you at two in the morning.
"Outbound buys you speed. Inbound buys you compounding. Neither one is free, and you can't skip the first because you're in love with the second."
Which should you run first?
Whichever matches the resource you actually have. Not the one that sounds more modern. Before either, the same first step: know exactly who your customer is and write it down, because marketing to everyone is marketing to no one. Then:
No budget, some hours: a three-person IT support firm with £0
Outbound first, plus the cheapest inbound there is. Lots of small businesses need IT support, it's a known pain, and buyers now research the answer heavily before they call anyone, so you need both the call and something for them to find. The recipe: define the ideal customer and sketch two avatars. Build the list, and this is an afternoon's work now: search Google Maps for the business types you want in your area and scrape the results into a spreadsheet with a free tool. Screen that list against the TPS and CTPS registers before you dial, because a scraped number is not permission and the fines are real (the law is in the cold calling article). Then a protected hour a day on the phone, and one useful post a week answering the question you heard most on yesterday's calls. That's the whole plan and it costs nothing but nerve.
Some budget, no time: a ten-person consultancy with £2,000 a month
Inbound first, but not only. Keep organic content going whatever else you do, because at this size it's the thing that compounds. Then define the ideal customer and the core offer, and put the money into one of two outbound shapes. Either buy data and run cold email at volume (how far £2,000 goes depends entirely on what the data costs), or build a small go-to-market stack: tools that watch for buying signals among the firms that fit your profile, so that when a signal fires, you jump on it that day instead of cold-calling the whole list. Either way, it takes twelve or more touches for someone to buy from you now, mixed across content, email, voicemail, LinkedIn messages and calls. The £2,000 buys you the touches you haven't got the hours to make.
The general rule
- No money, spare hours: cold calling plus organic content. It's the cheapest combination in marketing.
- Money, no hours: inbound engine first (content, search, a page that converts), outbound narrowed to the best-fit accounts and partly automated.
- Neither: referrals. Ask every happy client for one introduction. It's inbound you don't have to wait for.
- Regulated or trust-heavy service, like accountancy: I've never seen cold calling run for an accountancy firm and I won't pretend to know how it would go. For those I'd build organic content and paid search first.
The test that settles it, whatever your situation: does an hour of this make you more gross profit than an hour of that? Rough maths is fine. No maths is how people end up doing both badly.
How inbound and outbound feed each other
This is the bit nobody on page one explains, because they've only ever done one side. Outbound is market research with a phone. Every objection you hear and every question people ask you on a call is something they're typing into Google and ChatGPT too. If three prospects ask "do you do fixed-fee?" in a week, that's your next page, and because you've heard it in their words you'll write it better than any agency could. The bonus these days is that you can transcribe the calls and turn the transcript straight into content. Outbound tells you what to write. Inbound then answers the question before the next person has to ask it.
And it works the other way. Marketing makes you known, and known people get picked up. The difference in a call from someone who's seen your post is unmistakable: "oh yeah, I noticed you on LinkedIn the other day" turns a cold call into a warm one before you've said anything. It's the same effect as "oh, I know so-and-so". Every call is also the first of about twelve touches now, and the second touch happens the moment they hang up and look you up. If your website says something different from what you just said, you've lost them.
One warning, and it's the reason bad outbound is worse than no outbound. A spammy call or a lazy cold email doesn't just fail on its own terms. It becomes the first thing a prospect checks you against before they decide whether to read anything you've written. Inbound runs on trust, and outbound done badly spends it.
The evidence for combining the two is the best evidence in marketing, as long as you don't overstate it. Binet and Field's analysis of around a thousand campaign case studies for the IPA found that businesses which balance long-term brand building with short-term sales activation outperform those that do only one, with the balance drifting towards brand in financial services. That's a principle drawn from big campaigns, not an instruction to spend 60% of a small budget on awareness ads. For a five-person firm it means: keep something that creates conversations now, and keep something that makes you familiar for later, and never assume the second will do the first's job.
A simple sequence for a small B2B firm
- Month one. Define the customer, the offer, and one page of proof (what you do, for whom, with a number in it). Everything else is built on this.
- Months one to three. Outbound to a short, screened list for conversations now. One useful piece of content a week, written from what the calls taught you.
- Months three to twelve. Inbound starts to show. Narrow the outbound to the segments that answered, automate the touches you can, and keep publishing.
- Forever. Track leads by source and ask every enquiry "how did you hear about us?" That's how you find out which one is actually paying, and the measuring marketing guide shows how.
Sources: HubSpot, The 2011 State of Inbound Marketing (644 respondents, self-reported) and the 2012 State of Inbound (the 61% and 62% cost figures); Ahrefs, "How long does it take to rank in Google?" (2017, quote verbatim); British Chambers of Commerce and Intuit, The Turning Point for SMEs (2025); Gartner's 2017 B2B buyer survey (750 buyers; enterprise buying groups, so treated as direction only); Binet and Field, The Long and the Short of It and Effectiveness in Context (IPA Databank). Named as unreliable and not used: "content marketing costs 62% less and generates three times the leads" (no findable source), "90% of buyers research online first", "buyers are 57% through the journey before contacting sales", and the 95:5 rule as a law rather than a heuristic.