Deal announcements have a rhythm everyone in corporate communications knows. Weeks of secrecy, a dawn RNS, a choreographed morning of calls, a press release with the word “transformational” doing heavy lifting, and by evening, a sense in the deal team that the communications job is largely done.
However, the announcement to the financial markets and press is not the end of the communications work; it’s the opening claim in an argument that runs for months. According to Bain, M&A activity is booming again, with global deal value up 36% last year to $4.8 trillion, which means more organisations than ever are about to discover the hard way that the period after the press release is where deals are actually won or lost reputationally. The evidence on outcomes is famously brutal: studies have put the failure rate of mergers and acquisitions at anywhere between 70 and 90%, and the market prices in that scepticism from the first morning. Around 55% of acquirers see their share price fall on announcement. Whatever your press release says, the default position of the world is doubt and amongst the media, scepticism at best.
Which is why the first 100 days matter as much as day one. Five audiences heard your announcement, and every one of them spends the following months testing the story against what actually happens. Investors test the numbers, employees test the reassurances, customers test the service, media test the narrative, and regulators test the filings. The announcement made claims; the 100 days either honour them or quietly contradict them, and each audience is watching a different part of the story and developments since it was told.
Key takeaways
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The press release is the opening claim in a months-long argument, not the end of the communications job – the first 100 days determine whether the deal’s reputation holds.
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M&A is rebounding sharply (global deal value up 36% to $4.8 trillion, per Bain), but 70–90% of deals still fail, and roughly 55% of acquirers see their share price drop on announcement day. The market starts sceptical by default.
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Five audiences – investors, employees, customers, media and regulators – each test the announcement against what actually happens next, and they compare notes with each other.
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Three failure patterns recur: post-announcement silence (which rumour and competitors fill), a fractured story (as different functions improvise their own version), and neglect of internal communications (despite culture and people issues driving roughly a third of deals that miss their financial targets, per Mercer).
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Employee attrition after acquisition is nearly triple the normal rate, and over a quarter of acquirers have no retention plan for key people (WTW) – making integration communications a direct lever on deal value, not a “soft” workstream.
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The fix is structural: treat the 100 days as a planned campaign with a defined rhythm, and put one narrative owner in charge across investor relations, internal, customer and external channels.
Where the story breaks down
The failure patterns after announcements are remarkably consistent. The first common pattern is silence where the press office seemingly shuts up shop and the external storytelling is paused. Legal caution, regulatory constraint and sheer exhaustion combine to produce a communications void between announcement and close, and voids don’t stay empty. Employees fill them with rumour, media fill them with speculation, and competitors fill them with mischief aimed squarely at your customers and your best people.
The second issue we regularly see is the fractured or inconsistent story. The transaction narrative that was airtight on announcement morning starts developing in a way that means it is open to interpretation or is told in different ways. Investor relations emphasises synergies or efficiencies, which employees correctly translate as job losses. Sales teams improvise answers for anxious customers or over-promise in order to close a sale. Local managers freelance in town halls, off script and without communications input.
Within six weeks, five audiences are hearing five stories, and the inconsistencies get noticed, because these audiences talk to each other. Analysts read Glassdoor, journalists ring suppliers, employees read the analyst notes and media coverage.
The third is the forgotten inside; employees and the importance of internal communications. The commercial logic gets rehearsed for the City while the people expected to deliver it hear least of all. The cost of that neglect is well documented: culture and people issues are the reason roughly a third of deals fail to meet their financial targets, according to Mercer’s global study, which also found communication among the top drivers of culture outcomes. US Census data on thousands of tech acquisitions found a third of acquired employees gone within a year, nearly triple the rate of ordinary hires, and WTW’s research found 28% of acquirers had no retention plan for key people at all. Integration communications isn’t a soft workstream. It is, quite directly, synergy protection.
A rhythm for the 100 days
The antidote to all three failure modes is the same: treat the period as a planned campaign with a rhythm, an owner and a defined message for each stage, rather than a long tail of ad hoc reaction.
Underneath the whole rhythm, one structural rule: stakeholder communications needs a single narrative owner with authority across investor relations, internal, customer and external channels. The five audiences will compare notes and your story has to survive the comparison.
The finish line fallacy
The press release or RNS is the easiest part of deal communications: one document, one morning, total control. Everything that decides the deal’s reputation happens afterwards, in the long window where control is partial, attention is fading and five audiences are quietly marking your claims to market. The organisations that get M&A communications right simply plan for that window with the same rigour they gave the announcement, and it shows, in retention, in customer numbers, and eventually in whether the deal makes it out of the 70 to 90% or into it.
FAQs
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Why doesn’t the deal announcement itself settle the story? Because the audiences that matter – investors, employees, customers, media, regulators – don’t judge the deal on announcement morning. They judge it over the following months, testing the announcement’s claims against what actually happens. The release is a claim; the 100 days are the evidence.
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Why do so many acquirers see their share price fall on announcement? Roughly 55% do, reflecting a market that prices in scepticism by default – a reasonable stance given that 70–90% of M&A deals are estimated to fail. The onus is on the acquirer to prove the deal out, not the other way round.
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What’s the biggest mistake companies make right after announcing a deal? Going quiet. Legal caution and sheer exhaustion often shut down external storytelling between announcement and close, but that silence doesn’t stay empty – rumour, speculation and competitor mischief fill it instead.
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Why do different audiences end up hearing different versions of the story?Because different functions – investor relations, sales, local managers – improvise their own answers under pressure, often without central sign-off. Within weeks, five audiences are hearing five stories, and because those audiences talk to each other (analysts read Glassdoor, journalists ring suppliers), the inconsistencies surface fast.
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Why does internal communication matter so much to deal success?Because people deliver the synergies the deal was priced on. Culture and people issues are cited as the reason roughly a third of deals miss their financial targets (Mercer), acquired-employee attrition runs nearly triple normal rates within a year, and over a quarter of acquirers have no retention plan for key staff (WTW) – all of which make employee communications a direct protector of deal value.
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What should companies actually do differently?Treat the 100 days as a planned campaign, not ad hoc reaction: build a defined rhythm and message for each stage, and appoint a single narrative owner with authority across investor relations, internal, customer and external communications, since every audience will be comparing notes.
- When does the 100-day window actually end? Not on a fixed date – it ends when the five audiences stop actively testing the deal’s claims against reality and the narrative has effectively been “proven.” For most deals that’s a matter of months, not the literal 100 days, which functions more as a planning horizon than a hard deadline.
About the author
Simarin Tandon | Junior Digital Account Director
Having worked with brands across the Beauty & Wellness, FMCG, FinTech, and Home & Lifestyle sectors, Simarin focuses on driving acquisition and growth, whilst managing the Digital team at brandnation.
A curious marketer, Simarin’s finger is always on the pulse when it comes to performance and digital updates across both paid and organic platforms.
