Account engagement startup 6Sense today announced that it closed a $125 million series D funding round led by D1 Capital Partners, valuing the company at $2.1 billion post-money. 6Sense says that the investment will bolster its growth and product initiatives, particularly in the areas of machine next-best-action prediction, data insights, and AI-powered orchestration capabilities.

Business-to-business buyers are typically 57% of the way to a buying decision before they engage with sales departments. Moreover, only 23% of executives are confident in the speed at which they’re gaining accurate insights.

Motivated by the idea that AI might have a role to play in helping seal the deal, five entrepreneurs — Amanda Kahlow, Dustin Chang, Premal Shah, Shane Moriah, and Viral Bajaria — cofounded 6Sense in 2013.

6Sense’s product captures intent signals from known and anonymous sources including the web, creating customer segments by account, behavioral intent, or a combination of those two factors. 6Sense identifies contacts and builds out targeted buyer lists, helping to prioritize outreach sales efforts and boost conversions with machine learning-based fit scores. The platform also triggers marketing communications through apps like Marketo and Eloqua in response to sales prospects’ demands. Moreover, it enables salespeople to engage with buying teams via multichannel, multitouch campaigns.

Automation is now seen as essential among marketers to bolster the outreach of campaigns, in part because of its ability to better target customer communications. According to a recent HubSpot survey, email automation campaigns are among the top three tactics used by marketers to improve performance. And in 2017, Salesforce reported that 67% of sales leaders used a marketing automation platform.

Under the hood of 6Sense’s platform is a demand graph that captures signals and automatically connects them to sales prospects. Algorithms ingest historical intent data to reconstruct account-based buyer journeys for any given business, monitoring the demand graph and analyzing changes in intent to score hundreds of millions of accounts and people every day.

6Sense recently launched Segment Performance Reports and Custom Talking Points, two features that enable marketers to analyze changes in account engagement and progression through buying stages and provide guided conversation points based on buyer intent, role, and fit. February 2020 saw the introduction of Next Best Actions, which leverages AI to present business development representatives with a prioritized list of actions to engage buying teams within a target account.

6Sense competes to a degree with ZoomInfo. Other startups operating in the segment include Demandbase, which has raised over $150 million with backing from high-profile investors, as well as Lattice Engines and Leadspace.

But 6Sense backers aren’t concerned, and they have some reason to be optimistic. The year 2020 was the company’s third straight year of 100% revenue growth, 6Sense says, driven by “significant increases” in pipeline, revenue, average sale price, and deal velocity and a twofold increase in customer base size. (Brightcove and Cognizant are among 6Sense’s clients.) While global ad spend was predicted to have fallen 10.2% year-on-year in 2020, ad agencies including Magna say they expect to see ad spend to rise over 7% in 2021 to around $612 billion total, with digital media seeing growth exceeding 10%.

“We’re grateful for our success leading the account-based sales and marketing category — and humbled by the confidence our customers and investors have in 6Sense — but our vision has always been bigger and bolder,” said CEO Jason Zintak. “There is an enormous opportunity to redesign the way business-to-business companies go to market. We believe we have the platform, data, team, and investment partners to be the foundation for business-to-business revenue technology.”

Forrester predicts that spend for marketing automation tools will grow “vigorously” over the next few years, reaching $25.1 billion annually by 2023 from $11.4 billion in 2017. It’s estimated that 55% of marketing decision-makers plan to increase their spending on marketing technology including AI and machine learning, with one-fifth of the respondents expecting to increase by 10% or more.

“We invest heavily in sales and marketing technology, and 6Sense is truly one-of-a-kind,” Sapphire Ventures partner Rajeev Dham, a 6Sense investor, told VentureBeat. “We’ve always viewed 6Sense as a market leader with the ability to execute on their bold vision of transforming sales and marketing with data-driven insights and orchestration capabilities. 6Sense is already the leading account-based sales and marketing platform, and they are poised to define and deliver the future of revenue technology that every B2B organization needs.”

Beyond D1 Capital Partners and Sapphire Ventures, Insight Partners and Tiger Global participated in 6Sense’s latest funding round. It brings the 300-employee, San Francisco, California-based company’s total raised to date to over $225 million.