What You Can Legally Learn About a Competitor's Marketing (And Where the Line Sits)

Straight answer: you can legally learn almost everything about how a competitor markets themselves, their pricing, their ad spend, their email cadence, even their staff turnover, without ever breaking a law or a terms of service. You just have to know where to look and accept that most of what you find will tell you nothing useful. That second part is the bit nobody wants to say out loud.

Why I started digging through competitors' marketing again

I stopped doing proper competitor research for a stretch of years. When you're rebuilding a consultancy from nothing, which is exactly what I've been doing publicly for the last five years, you spend your time on your own clients, not stalking other people's inboxes.

Then a client, a small B2B software company in Reading with about 40 staff, asked me a question I couldn't answer with a straight face: "How does our biggest competitor keep winning our deals at a higher price than us?" So I went and found out, legally, in about three afternoons. What I found wasn't a secret weapon. It was one email sequence, a pricing page that had been quietly rewritten, and a LinkedIn hiring spree that told me everything about where they were pointing their budget next.

What's fully fair game, no grey area at all

These are things you can look at, sign up for, download, and screenshot without a single legal worry:

• Their public website and pricing pages. Everything published for the world to see is yours to read, compare, and act on.
• Their email newsletter. Sign up with a spare email address and watch what they send. This is the single most underused source of intelligence I know.
• Their paid ads. Meta's Ad Library shows every ad a Facebook or Instagram page is running right now, including the copy, the image, and how long it's been live. Google doesn't offer the same full transparency, but tools like SEMrush and SimilarWeb show estimated ad spend and top keywords.
• Companies House filings. Any UK limited company's accounts are public. You can see turnover bands, director changes, and sometimes staff numbers. It costs nothing and takes ten minutes.
• Job postings. A competitor advertising for a "Head of Lifecycle Marketing" is telling you, loudly, that email and retention are about to become their focus. I use this constantly.
• Glassdoor and LinkedIn reviews. Staff reviews leak more strategy detail than most marketing directors realise, especially about internal targets and what leadership is obsessing over.
• The Wayback Machine. Free, and it shows you exactly how a competitor's messaging, pricing, and homepage have changed over time. It's one of the tools I recommend most when people ask me about legal ways to spy on competitors' websites, because it's completely open and nobody has to know you're looking.

The step-by-step version I use

Here's the process, start to finish, that I ran for that Reading client. It took roughly six hours spread over three afternoons.

• Step 1 (20 minutes): Pull their Companies House filing and note revenue trend and headcount growth over the last three years.
• Step 2 (30 minutes): Search their name in the Meta Ad Library and note how many ads are live, how old the oldest one is, and what the offer is in each.
• Step 3 (1 hour): Sign up for their email list from a fresh address, then check back weekly for eight weeks. Log every email, subject line, and offer in a simple spreadsheet.
• Step 4 (1 hour): Run their domain through SimilarWeb and SEMrush to see estimated traffic, top pages, and top keywords.
• Step 5 (30 minutes): Check their careers page and LinkedIn jobs for every open role posted in the last 60 days.
• Step 6 (1 hour): Read the last 20 Glassdoor reviews and every recent LinkedIn post from their leadership team.
• Step 7 (1 hour): Pull it all into one page and write down what changed and when, not just what exists now.

For that client, the finding that mattered wasn't the ads or the pricing. It was that the competitor had posted three roles for "Customer Success" in one month while cutting one sales role. They weren't winning by outspending on marketing. They were winning by keeping existing customers longer and letting referrals do the selling. No amount of ad-spy tools would have told us that. The job board did.

Where legal research quietly turns into something else

This is the part most articles on this topic skate straight past, and it matters more than any tool list.

Reading a public email is legal. Creating a fake company identity to get a demo call and pricing that's meant only for prospective buyers, then handing that pricing straight to a rival business, sits in murkier territory, especially if you misrepresent who you are to get information not otherwise public. Scraping a website against its published terms of service isn't automatically illegal in the UK, but it can breach contract law and get you cut off, blacklisted, or sued for breach of terms, depending on what you scraped and how aggressively. Posing as a journalist or investor to extract non-public financials is straightforwardly deceptive and can expose you to fraud claims. None of that is common, but I've seen agencies get close to the line without realising it, usually because someone junior was told to "find out everything" with no boundary given.

My rule of thumb: if you'd be embarrassed explaining exactly how you got a piece of information to the competitor's face, don't collect it that way.

The uncomfortable bit nobody wants to admit

Here's the truth I don't see written down anywhere else on this topic: doing all of this research will not fix a weak offer, a confused positioning statement, or a product that's worse. I've watched businesses spend two weeks building a beautiful competitor teardown deck, present it to the board, feel very clever, and change nothing about their own product afterwards because the real problem was never a lack of information. It was that nobody wanted to make the harder decision the research pointed to.

The Reading client I mentioned didn't need more competitor research. They needed to move two people from sales into customer success, which is uncomfortable, political, and slow. The research was easy. Acting on it wasn't. That's true almost every time.

A shorter, cheaper version if you don't have six hours

If you've only got 45 minutes, do three things: sign up for their newsletter, check the Meta Ad Library, and read their five most recent job postings. That combination alone tells you what they're selling right now, how hard they're pushing it, and where their budget is heading next quarter. It's roughly 80% of the value for 10% of the time.

Tools worth knowing, none of which require a login you shouldn't have

• SimilarWeb for traffic estimates and top referring sources.
• SEMrush or Ahrefs for keyword rankings and estimated ad spend.
• Meta Ad Library for live Facebook and Instagram ads, completely free.
• Milled or MailCharts for archived marketing emails from thousands of brands, useful if you don't want to wait eight weeks for your own inbox to fill up.
• Wayback Machine for historical website versions.
• Companies House for UK financial filings, or the SEC EDGAR database for US public companies.

If any of this competitive picture connects back to your own email strategy, it's worth reading through what email marketing involves day to day, because half the point of watching a competitor's sends is figuring out what you should be doing with your own list instead.

What this changes about how you compete

Once you've done this a few times, the pattern becomes obvious: your competitors are not hiding a secret. They're running a version of the same playbook everyone runs, just with different timing and different budget. The businesses that win aren't the ones with the best-kept secret marketing tactic. They're the ones who act fast on plain, public information while everyone else is still building the spreadsheet.

If you're building any of this into an AI-assisted workflow, whether that's scraping public ad libraries, summarising email archives, or drafting comparison content off the back of it, it's worth understanding how far AI tools can take this without crossing into anything shady. I've written before about learning AI from scratch in 90 days, and a good chunk of that applies directly to research like this, because the tools change every few months but the ethics don't.

And if your own output at the end of this research is a comparison page, a landing page, or an ad set, don't overlook the visual side. Competitors with weak creative are often the easiest to beat on pure attention, and knowing how to use an AI image generator for your marketing is often the fastest way to close that gap without hiring a design agency.

Related: writing for us on growth marketing.

Related: the legal page.

Frequently asked questions

Is it legal to sign up for a competitor's email list to see what they send?

Yes. Signing up for a publicly available newsletter with a real or spare email address is completely legal and is one of the most useful things you can do, since it shows you their actual offers, cadence, and tone over time rather than a snapshot.

Can I use fake company details to get a competitor's pricing?

You can request pricing as a genuine prospective customer, but deliberately impersonating a specific person or misrepresenting who you are to extract non-public information moves from legal grey area into deceptive practice, which can create real legal exposure depending on what you do with the information afterward.

Is scraping a competitor's website against their terms of service illegal?

It's usually a breach of contract rather than a criminal act in most cases, but it can still get you blocked, blacklisted, or subject to a legal claim from the site owner, so it's worth reading the terms before you build any scraping process into a regular workflow.

What's the single most useful legal source for competitor intelligence?

Job postings, consistently. A hiring pattern tells you where a competitor is about to put budget and focus months before it shows up in their marketing, and it's completely public.