Demand gen: broadcast and attract
Demand generation casts wide. The goal is to build awareness and interest in a broad audience through content, SEO, paid ads, social, and events, and let qualified buyers self-select into your funnel. You create the conditions for demand to exist, then capture it when people come looking.
Demand gen wins when: your total addressable market is large, your deal sizes are smaller, your sales cycles are short, or you're building a category from scratch and need volume at the top of the funnel.
ABM: focus and pursue
Account-based marketing starts with the accounts it wants and works backward. No waiting for the right people to find you. You go to them, deliberately, across multiple channels, until they know who you are and what you do.
ABM wins when: you have a clearly defined ideal customer, your deal sizes justify deeper investment per account, your sales cycle is long enough that relationship-building matters, or you're selling to a finite universe of potential customers where volume-based demand gen would simply run out of audience.
The real difference
Demand gen optimizes for quantity of inbound: more leads, more traffic, more pipeline from wherever it comes. ABM optimizes for quality and focus: more revenue from a specific, prioritized list of accounts, regardless of whether they raised their hand first.
Demand gen asks: "How do we get more people interested?" ABM asks: "How do we get these specific people interested?"
Why most teams need both
Neither approach handles every situation perfectly. Demand gen alone means you're at the mercy of whoever decides to show up. ABM alone means you're ignoring a potentially huge pool of buyers who'd come to you with the right content pull. Most scaled B2B teams run demand gen to build broad market presence while ABM handles the specific accounts where focused effort has the highest return.
Demand gen attracts anyone who might be interested. ABM pursues exactly who you want. One builds a funnel; the other builds a shortlist.