PROBOOK.US
The United States market, secured under one name.
The extension chosen by zoom.us to build a $26B company.
A premium .us domain delivering complete US-market brand coverage for the Probook identity — available for immediate acquisition at $35,500.
Zoom Video Communications built one of the fastest-growing SaaS companies in history on zoom.us — an extension that reinforced its US-market identity from day one. The .us signalled domestic authority, regulatory alignment, and institutional trust that global TLDs simply do not convey. Today, zoom.us serves billions of visits per month as a primary destination, alongside a $26B market cap and near-universal brand recognition. The lesson is clear: a great .us domain is not a compromise or a fallback — it is a category-defining brand asset that compounds with the company built alongside it. For any brand whose core market is the United States, the .us extension is a positioning statement, not a placeholder.
Same structure. Same clarity. Same category-defining opportunity — thirteen years earlier registered.
One brand. The entire US market.
Probook.us closes the most important gap in any US-focused brand strategy — complete domestic coverage under the same clean, two-syllable name that audiences already recognise.
letters — clean, pronounceable, and instantly understood. A name that functions as both a noun and a verb across professional services, platforms, and applications.
The official country-code TLD for the United States — trusted by government institutions, enterprises, and consumers nationwide. Exclusive to US-market entities.
Asking price. Representing the US-market value of the Probook brand identity — and a fraction of what brand gap exposure costs at scale.
strategic acquisition profiles across professional services, knowledge platforms, AI SaaS, and booking infrastructure — all served by owning this name in the US market.
Who acquires Probook.us next?
Four distinct acquirer profiles — each building a category-defining US-market brand on a name that is already recognised and trusted.
Professional Services Portal
"ProBook your professional."
A credentialing and discovery platform for lawyers, accountants, engineers, architects, and business advisors serving the US market. LinkedIn meets Avvo meets Bark — with a name that already says exactly what it does, anchored to the US audience that matters most.
Professional Books Marketplace
O'Reilly for US professionals.
A vertical marketplace or subscription library for professional-grade titles: law, accounting, engineering, MBA, CFA, CPA and exam preparation for the US market. The .us extension signals domestic authority and regulatory alignment from the first click.
AI-Powered Professional Platform
Your US professional operating system.
An AI tool suite for US professional services firms — document automation, client management, knowledge management, and billing. For regulated US industries where domestic brand presence carries compliance credibility, .us is a strategic asset, not just a URL.
Professional Booking Engine
Book a US professional in 60 seconds.
A scheduling and booking platform for US-based lawyers, consultants, advisors, and coaches. "Pro" plus "book" reads as a verb — and the .us extension positions this platform as the definitive domestic destination for professional access.
Across every category of US technology and consumer brand, owning the .us extension is standard practice — not an afterthought. The companies below represent a cross-section of how America's most recognisable brands treat country-code coverage: as a baseline, not a luxury. The pattern is consistent. The brands that matter in the United States own their .us.
| # | .us Domain | Category / Brand | Valuation / Market Cap | Role | What It Signals |
|---|---|---|---|---|---|
| Primary Domain — .us as the brand's main address | |||||
| 1 | zoom.us | Video / SaaS · Zoom | $26B market cap (2026) | PRIMARY | Built a $26B NASDAQ company on .us from day one. Acquired zoom.com for $2M only after becoming a unicorn — and still operates primarily on .us. |
| 2 | curb.us | Mobility / Booking · Curb | $100M+ (est.) | PRIMARY | NYC-based ride and taxi booking platform. Operates natively on curb.us — US-first identity built into the brand from launch. |
| 3 | del.icio.us | Social / Bookmarking · Delicious | Acquired by Yahoo! (2005) | PRIMARY | One of Web 2.0's most iconic brands was built entirely on a .us domain hack. Yahoo acquired it in 2005 — the .us address was central to its identity. |
| 4 | about.us | Identity / Profiles · About.us | $10M+ (est.) | PRIMARY | Professional identity and bio platform operating natively on .us — the extension became the product's entire positioning hook. |
| 5 | driv.us | Automotive / Services · Driv | Private | PRIMARY | US automotive services platform built on .us as its primary consumer-facing domain — domestically anchored by design. |
| Defensive Hold — .us secured alongside primary .com | |||||
| 6 | robinhood.us | Fintech / Investing · Robinhood | $103B market cap (2026) | DEFENSIVE | US-regulated brokerage — .us closes domestic brand gap for a $103B platform with 27M active US accounts. |
| 7 | hulu.us | Streaming / Media · Hulu | $27.5B (Disney, 2025) | DEFENSIVE | Disney paid $9B for full ownership. A $27.5B US streaming brand holds .us as standard brand hygiene. |
| 8 | venmo.us | Payments / Fintech · Venmo | ~$38B implied (PayPal) | DEFENSIVE | 97M US users, $270B annual payment volume. PayPal holds venmo.us to protect the dominant US P2P payments brand. |
| 9 | cashapp.us | Payments / Block · Cash App | $40B+ (Block, 2025) | DEFENSIVE | Block holds cashapp.us alongside cash.app — dual-domain protection for its flagship US consumer product. |
| 10 | trulia.us | Real Estate · Trulia | $3.5B (Zillow, 2015) | DEFENSIVE | Zillow paid $3.5B for Trulia. The combined entity holds trulia.us — geographic brand coverage for a location-dependent US market. |
| 11 | disqus.us | Media / Publishing · Disqus | ~$90M (Zeta Global) | DEFENSIVE | Holds disqus.us to protect brand identity across its US publisher network of 2B+ monthly users. |
The .us extension is restricted to US-based entities by ICANN policy — making it a defensible, exclusive asset. Once acquired, it is closed.
Reported transactions and brand precedents illustrating the value of owning a brand's country-code extension alongside its primary domain. The cost of not owning it is measured in lost traffic, brand dilution, and competitive exposure.
| Domain / Brand | Reported Value | Context |
|---|---|---|
| zoom.us | $20B+ company | Built entirely on .us. Acquired zoom.com for $2M in 2018 — after becoming a unicorn. The .us was the brand. |
| defense.gov / nasa.gov | Institutional | US government and federal agencies use .gov/.us as the definitive signal of domestic authority — setting the trust standard for all .us domains. |
| Lawyers.com | $650,000+ | Acquired by Martindale-Hubbell — exact-match professional services category, US-focused audience. |
| Connect.com | $10M (2022) | Acquired by HubSpot — professional networking brand. US market is the primary value driver for compound professional domains. |
| Booking.com | $15B+ brand | Supreme Court precedent: a generic-compound domain can anchor a global brand. Country-code coverage closes the brand loop domestically. |
| Procore.com | $9B IPO | US construction SaaS built on a "Pro" prefix brand — US-first expansion, demonstrating the domestic market premium for Pro-prefix names. |
| Probook.us | $35,500 | Asking price. US-market brand coverage under the Probook identity. Available for immediate acquisition. |
Acquire Probook.us
The domain is held by its owner and offered for direct sale at $35,500. Serious enquiries are reviewed within 48 hours, and a transaction can complete in days through Escrow.com.
The .us extension is restricted to US-based entities, making this a defensible, exclusive asset. Once acquired, the Probook brand identity in the United States market is fully closed to competitors.
All transactions complete through Escrow.com or an equivalent licensed escrow service. Funds release only on confirmed transfer of the domain to the buyer's registrar account.