Earlier quoted context omitted.
Advertising is only a small portion of marketing. Probably 1/3rd of 1 persons job is spending that $3k media spend. The rest of the team works on things like branding, identifying markets/customers, picking price points, running tables at events, writing content, working on the website, researching potential new products, understanding how current users use the products, analyzing web site traffic for insights, etc.…
I would do more sales...
For low touch sales cycle company like Buffer, marketing is sales.