Can you share advice for the first product marketer at a company for influencing the product roadmap?

Sure, as the first product marketer, you need to arm yourself with customer insights (be the voice of the customer), be able to clearly define who you're selling to, what is their role, how do they make decisions, what are their pain points, how is your company uniquely addressing those key areas, what does the competitive ecosystem look like, how do they price, what's the win/loss ratio? Do you have data and information on lost customers? What's the plan to acquire net new customers?

These can all help you inform and influence the product roadmap .

The first thing I would recommend is to understand your company’s definition and expectations for Product Marketing. Be prepared that it may be a narrow definition and as a result you may be seen as a service/support function vs. a strategic partner. It’s common for the first PMM to either become a jack of all trades or to just focus on the tactics of carrying out GTM instead of on the strategy behind it.

I give a few pieces of advice on earlier questions for how to show value so that you are viewed as a thought partner.

Another area you should focus is having a repeatable and scalable GTM process with playbooks and messaging frameworks - since in the beginning this will likely be a big portion of your day-to-day. Having this structure early on will prevent last minute scrambles so you have more time to take on more of the work that positions you as a partner.

Focus on developing strong relationships with engineering and bringing a point of view to the table that is based upon data and insights that you gather from both first party and second party research, customer/partner/sales conversations and analyst engagements. You should be the voice of the customer and bring in the prespective of the market. 

Keep a stack-ranked list of the top product/feature requests that you hear from customers. As the product marketer, you represent the voice of the customer within the organization. Bring that voice to life by knowing their needs, where the product has gaps, and which features or enhancements will have the most significant impact.