When, in Season 6, Peggy shares Stan's SCDP insider information with Ted, noting that the Heinz Ketchup executive had met surreptitiously with SCDP but there was friction between him and Heinz Beans executive Raymond Geiger (an SCDP client).
Ted sees an opportunity and pressures Peggy to "find out everything you know about Heinz Ketchup." In "To Have and To Hold", Chaough's team encounters Don's in the hallway in front of the room where firms are making their Heinz pitches, and Don is shocked to see Peggy there—in the end, Heinz chooses a third (larger) firm, and Raymond Geiger drops SCDP because he feels betrayed.
He later becomes a founding partner at Sterling Cooper Draper Pryce.
Draper is the series' protagonist, and more storylines focus on him than on other characters.
Ted agrees, and the two firms merge, much to the surprise of everyone concerned.