What Sincerely does

Sincerely, operating through its Sinceerly product, is a single-purpose Chrome extension launched in 2025 by Harvard Business School student and Dorm Room Fund investment partner Ben Horwitz. The extension uses Anthropic's Claude AI to rewrite AI-generated email text in the opposite direction of conventional writing assistants, intentionally injecting typos, stripping em-dashes, and adding slang or abbreviations so the output appears more authentically human. Three progressive editing modes (Subtle, Human, CEO) allow users to dial up the level of intentional degradation, with the framing positioned by media coverage as the "anti-Grammarly."

The business model is a freemium pay-as-you-go structure: users receive a small allotment of free transformations and then pay a one-time $4.99 charge for continued access. There is no recurring subscription, no enterprise tier, no API, and no SDK; distribution is entirely self-serve through the Chrome Web Store with no sales force or channel partners. GTM is product-led and community-led, leaning on viral earned media in outlets such as Gizmodo, Fast Company, and WebProNews, as well as word-of-mouth driven by the tool's satirical framing around "AI slop." Marketing spend appears to be zero.

The primary customer segment is horizontal: business professionals who use AI writing tools and want their automated correspondence to evade growing scrutiny of AI-authored prose. Quantified evidence cited in source coverage is a small cold-email pilot in which four of five Fortune 500 CEOs replied to messages rewritten with Sinceerly. A notable caveat for any investment thesis is that the founder explicitly characterizes the venture as a joke and social commentary rather than a commercial ambition, and the 11-50 employee firmographic count appears inconsistent with the single-developer operational profile described in primary sources. A separate 2011 Series 2 funding round for an apparently unrelated prior Sincerely entity (a gifting network, $3M from Spark Capital, CRV, First Round Capital, SV Angel) is in the data and should not be conflated with the current product.

Name

Sincerely

Website

https://sincerely.com

Company type

Private

Founded year

2025

Operating status

Operating

Headcount range

11–50 employees

Short description

Sincerely operates Sinceerly, a Chrome extension that uses Anthropic's Claude AI to make AI-generated emails sound more human by injecting typos and stylistic quirks, sold to individual professionals via a $4.99 freemium pay-as-you-go model.

Ownership category

akta.pro rank

Headquarters

HQ city

San Francisco

HQ country

United States

HQ region

North America

Markets served

GTM type

B2C

Offering type

Software

Cost components

Technology or R&D, Marketing or Sales, Personnel, Infrastructure

Revenue model

1. Chrome Extension Downloads: Extension provides a limited number of free uses before charging for continued access, converting users after initial trial

Pricing tiers

Go-to-market motion2 records

Distribution channels1 record

Marketing channels3 records

Core offering

Sincerely offers Sinceerly, a Chrome extension that rewrites AI-generated text to sound more human by injecting intentional typos, removing em-dashes, and adding stylistic quirks. Built on Anthropic's Claude AI, it provides three progressive editing modes (Subtle, Human, CEO) that introduce increasing levels of slang, abbreviations, and misspellings to counteract AI-sounding writing in professional communications.

Product overview

Sinceerly is a single-purpose Chrome extension that modifies AI-generated emails to appear more human-written. The product offers three editing modes—Subtle, Human, and CEO—that progressively introduce more typos, slang, abbreviations, and other imperfections. Built using Anthropic's Claude AI, the extension provides a few free uses before charging $4.99. The creator describes it as tongue-in-cheek satire rather than a serious product, serving as social commentary on the proliferation of AI-generated content in professional communications.

Differentiator

Problem solved

Functional benefit

Products and services

• Sinceerly Chrome Extension Chrome extension and AI-powered web app that rewrites AI-generated text to make it sound more human by injecting intentional typos, removing em-dashes, and adding stylistic quirks. Offers three editing modes (Subtle, Human, CEO) with progressive levels of text degradation to mimic authentic human writing. Target users are individual professionals who want their AI-assisted emails to appear more authentically human-written.

Quantifiable outcome

• 4 out of 5 Fortune 500 CEOs replied when cold-emailed using Sinceerly-modified messages

Segments2 records

Ideal customer profiles1 record

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability2 records

Feature2 records

Partnerships

One partnership is on record.

• AnthropiccoreTechnology or IntegrationSinceerly is built using Anthropic's Claude AI as the underlying technology. Anthropic provides the AI foundation that powers the text humanization engine, making Claude the core technical component of the product.

Scale indicators1 record

Recent moves4 records

Expansion highlights2 records

Broad incumbents

• 1-800-Flowers.com: Public, large-scale online gifting retailer offering flowers, gift baskets, and personalized gifts across consumer and corporate channels. Directly comparable to Sincerely as a multi-category gifting network, though significantly larger, more diversified (owns Harry & David, Shari's Berries, Personalization Mall, Wolferman's), and publicly traded.
• FTD Companies: Long-standing floral and gift delivery network now operating as a subsidiary of 1-800-Flowers. Comparable to Sincerely as a multi-merchant gifting marketplace, although FTD pivoted business model and was delisted/acquired multiple times, making it a relevant structural reference for what happens to legacy gifting networks under capital duress.

Direct peers

• GiftTree: Online specialty gift retailer offering gift baskets, gourmet foods, wine, and personalized gifts with strong corporate-gifting channels. Closely comparable product mix and target customer for Sincerely's gift-of-all-types network positioning.
• UrbanStems: DTC online flower and gift delivery startup founded around the same era as Sincerely; competes in the same consumer gifting vertical with curated gift sets and direct-to-consumer fulfillment. Closest in age, geography (US-based), and product focus.
• Sendoso: Corporate gifting and direct mail automation platform — among the leading venture-backed plays in the broader gifting network category. Comparable to Sincerely in the gifting-network category but targeted at B2B sales/marketing use cases rather than consumer gifting.
• The Bouqs Company: DTC online florist and gifting brand founded in 2012 in California, sourcing directly from growers and shipping flowers and curated gifts. Comparable to Sincerely by virtue of overlapping product (flowers + gifts), era (early 2010s launch), and target market (US consumers/corporate gifting).
• BloomNation: Online floral marketplace connecting consumers with local florists for direct delivery. Comparable marketplace/network model to a "gifting network" concept, although narrower scope (flowers only).

Emerging players

• Alyce (formerly Sendoso competitor): B2B gifting and swag platform (formerly Reachdesk) using AI to help sales teams send personalized gifts at scale. Comparable to Sincerely as a gifting network serving workplace/professional communications use cases, the segment Sincerely originally targeted.
• Loop & Tie: Corporate gifting startup offering gift-choice platforms that let recipients pick from curated gift collections. Comparable to Sincerely's gifting network thesis in the B2B / corporate gifting use case, and representative of the post-2010 wave of venture-backed gifting networks.
• Goody: Tech-enabled corporate gifting platform for sending gifts and swag directly from a dashboard, with social-recipient features. Comparable to a modern incarnation of Sincerely's gifting-network thesis applied to workplace gifting.

Market position

Strengths3 records

Weaknesses4 records

Competitive moat4 records

Key risks5 records

Key highlights4 records

Customer concentration

• Xx.com/Sincerely
• Facebookfacebook.com/sincerelyinc

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds1 record

Investors4 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Sincerely