How can product marketing be tied to the upselling and cross selling revenues of a company
There's plenty of ways Product Marketing can be at the heart of cross-sell/upsell campaigns. A lot of it ties into core product marketing skillsets and responsibilities -- persona development, positioning and messaging, enablement materials, market knowledge and measurement, and more.
More specifically:
Customer Segmentation & Personas - Based on all the work you've done to develop personas, now you can put it to work and identify segments of customers that are most likely to upgrade or purchase another product.
Messaging - Consider the messaging your marketing team, and sales team, will need when running a cross-sell/upsell campaign. Think through all the variations of cross-sell/upsell, and personas on the buying committee it most applies to.
Sales Enablement Materials - Beyond just messaging, think about the materials (one pagers, pitch-decks, case studies, website content, etc) Sales will need to effectively tell the story to power this campaign.
These are just a few examples but showcase how product marketing can be tied to cross-sell/upsell campaigns.