Forrester benchmark data shows that existing customers represent about three-quarters of B2B revenue. Portfolio marketers, however, often focus on new buyers and don’t always make the necessary adjustments required to adapt their go-to-market strategies to existing customers, potentially overlooking a significant source of revenue. In this report, we present a systematic way to look at targeting buyers within existing accounts — and what elements of go-to-market strategy need to be adjusted to ensure better engagement based on opportunity type.