Offering a client an additional, complementary service alongside what they came for — like a logo buyer who also needs business cards.
A cross-sell moves a client sideways into something related. They hired you for a logo; you offer matching business cards and social templates. They booked a photo shoot; you offer video coverage too. It’s a different service than the one they came for, but one that naturally fits the same need.
For sellers, cross-selling grows a project’s value without hunting for new clients. The trick is relevance — the add-on has to genuinely complete what they’re doing, or it reads as a cash grab. Bundling related services also makes you more useful: a client who can get three things done in one place has less reason to shop around.
For buyers, a smart cross-sell saves you the hassle of finding and briefing a second freelancer for something connected. Just make sure the add-on is something you’d have needed anyway, not filler.
Don’t mix it up with an upsell, which is more of the same thing rather than something new. Both raise a client’s lifetime value and both get easier when you package your services so complementary offers sit right next to each other.