Palantir is a high-touch, B2B enterprise software startup, and as such, they are no different than other startups when it comes to sales&marketing. They need to find leads (= potential customers), close them as customers and retain them.
Yet, Palantir's leadership and employees have repeatedly emphasized that they don't do sales or marketing. The OP confirms that they meant that they do sales and marketing differently than other companies.
Retaining lobbyists and policy advisers is one example. Typically, enterprise software companies retain industry analyst firms like Gartner, Forrester, etc. and "influence" their opinions via briefing/consulting. These industry analyst firms also work with technology buyers and make recommendations to them based on their knowledge of software/service providers and the needs of the buyer.
To be sure, no analyst firm is 100% pay to play because if they favor select vendors too much, they lose credibility, access to information and hence influence. That said, it's naive to think that they are 100% free from monied vendor incentives.
It did not occur to me until reading this post that the same model applies to lobbying, and that's where Palantir invested their influencer marketing budget.
Palantir often emphasizes their technological innovation and unique culture (again, a great marketing strategy to attract great technical talent and put them in sales engineering roles). However, I've come to believe that Palantir's greatest innovation is in their business strategy.