Last updated: 2026-05-12Confidence:medium-highSources:OnTheMarket company disclosures and AIM filingsCoStar Group acquisition announcement (December 2023)Companies House filings (Agents' Mutual Ltd, Glanty Ltd)GPPI primary research and public portal dataMethodology:vGPPI v2.1
Informational profile summary based on GPPI research and public information. Not legal, financial, or investment advice.
GPPI Summary
OnTheMarket is a UK residential property portal founded in 2015 by an agent-backed consortium and acquired by CoStar Group for £99M in December 2023. Operating across sales, lettings, and new homes, it serves approximately 14,000 advertiser branches. CoStar is investing ~£45–47M per year in UK consumer marketing to challenge Rightmove's dominance, driving strong consumer traffic growth from a low base. Its 'Only With Us' exclusivity proposition — offering early-access listings before rival portals — remains its primary competitive differentiator in the UK portal market.
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- 1.Founded in 2015 by Agents' Mutual, an agent-backed consortium challenging incumbent portals
- 2.Acquired by CoStar Group (NASDAQ: CSGP) in December 2023 for £99M (~2.5x revenue)
- 3.~14,000 advertiser branches; ~4,000 'Only With Us' exclusive listings per month
- 4.CoStar committing ~£45–47M/year in UK consumer marketing to grow portal market share
GPPI Answer Box: OnTheMarket
A quick reference.
- -UK residential portal serving sales, lettings, new homes, and commercial search
- -Owned by CoStar Group — US-listed data and analytics giant with ~$30bn market cap
- -'Only With Us' early-access exclusivity programme: listings visible 24h+ before rival portals
- -FY2023 revenue: £34.4M (~$43M); acquired at ~11x adjusted EBITDA
- -Faces entrenched competition from Rightmove (dominant) and Zoopla (established)
Domain
onthemarket.com
Headquarters
London E14, UK (CoStar UK entity)
Founded
2015
Core market
United Kingdom residential property
Geographies served
United Kingdom; overseas listings section
Marketplace type
Vertical classifieds B2B2C
Monetization
Agent subscriptions, new-homes advertising, featured placements, lead-gen referrals
Ownership
CoStar Group, Inc. (NASDAQ: CSGP); acquired December 2023 for £99M
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- 1.Revenue stream: Agent branch subscriptions — recurring annual/monthly fees from ~14,000 UK advertiser branches for residential sales and lettings listings
- 2.Revenue stream: New-homes developer advertising — paid placements and feature products targeting housebuilders and residential developers promoting new-build schemes
- 3.Revenue stream: Featured listings and branding placements — premium visibility products sold to agents including featured properties and branch branding upgrades
- 4.Revenue stream: Lead-gen referral partnerships — referral revenue from mortgage, conveyancing, and property valuation partners accessed via consumer journeys on-portal
- 5.Revenue stream: Display advertising — onsite display formats served to property-related advertisers including financial services and home-services brands
- 1.Only With Us exclusivity programme — early-access listing mechanism giving OnTheMarket 24+ hour exclusivity on new instructions before rival portals, displayed with a visible countdown timer to create consumer urgency
- 2.Portal search (sales, lettings, new homes, commercial, overseas) — unified property search with keyword search, map-based browsing, alert subscriptions, and guided 'Help Me Choose' decision journeys
- 3.Valuation journey — in-portal instant and agent-based valuation tool connecting vendors and landlords to local agents and generating lead-gen referral revenue
- 4.Agent CRM integrations — API/feed integrations with major UK estate agency CRM platforms enabling automated listing syndication and lead routing
- 5.Mobile apps (iOS and Android) — native property search apps with alert management, saved search, and agent enquiry functionality; Android 1M+ installs, iOS ~4.7/5 rating
- 6.Agent advertising and branding tools — featured listing placements, branch branding/spotlight products, and performance reporting dashboard for advertiser branches
- 1.Rightmove network-effect dominance — Rightmove's audience scale and agent dependency create a self-reinforcing flywheel; consumer marketing spend alone does not guarantee sustained traffic share shifts, and the portal has not historically broken Rightmove's lead
- 2.Agent multi-homing and subscription pressure — UK estate and lettings agents routinely subscribe to multiple portals; during cost-cutting cycles, OnTheMarket is typically the first subscription to be reduced or cancelled given lower perceived consumer reach relative to Rightmove and Zoopla
- 3.ASA and advertising standards scrutiny — OnTheMarket has previously attracted Advertising Standards Authority attention over comparative advertising claims (e.g. exclusivity and consumer reach assertions); continued aggressive consumer marketing under CoStar investment increases this exposure
- 4.GDPR and data compliance obligations — as a consumer-facing property marketplace handling significant volumes of personal data from enquiries, valuations, and user accounts, ongoing UK GDPR compliance represents an operational and reputational risk
- 5.Execution risk on CoStar investment thesis — the £99M acquisition price and ~£45–47M/year S&M commitment represent a significant capital outlay; failure to convert marketing spend into durable consumer market share and ARPU uplift would pressure the investment rationale and could trigger strategic review of the UK strategy
- 1.Consumer market share capture via sustained S&M investment — CoStar's committed ~£45–47M/year UK marketing budget is designed to drive brand awareness and direct traffic, with the goal of reaching a consumer audience comparable to Rightmove; early post-acquisition traffic growth of ~90% from a low base suggests the investment is gaining traction
- 2.ARPU uplift from low subscription base — at an estimated ~$3,200/year per branch versus Rightmove's significantly higher ARPU, OnTheMarket has meaningful headroom to increase subscription pricing and upsell premium products as portal audience metrics improve
- 3.New-homes depth and developer solutions — the UK new-homes market remains underserved digitally; deeper developer-facing tools, site-level content, and integrated sales-progress tracking would increase stickiness and revenues from housebuilder advertisers
- 4.Valuation, mortgage, and conveyancing lead-gen at scale — in-portal consumer journeys for valuation requests, mortgage comparisons, and conveyancing referrals represent high-margin revenue streams that grow proportionally with consumer traffic; CoStar's investment should amplify this flywheel
- 5.Homes.com brand and technology synergies — CoStar's parallel US residential portal build under the Homes.com brand may yield product, technology, and data synergies deployable in the UK market, accelerating OnTheMarket's feature roadmap at lower marginal cost
About this profile
This GPPI portal profile is an analytic summary prepared from GPPI research inputs including public information, company disclosures, and GPPI methodology. It is not a commercial endorsement. GPPI v2.1.
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