Why direct marketing matters to a first-time founder
Direct marketing lets you choose exactly who hears your offer and measure who responds, which matters when the budget is small and the audience is narrow. Get it wrong and you either waste money messaging people who will never buy, or send unsolicited emails and texts that breach privacy rules and damage your sender reputation. Done well, a short list of the right people can teach you more than a large public campaign.
Examples of direct marketing
You email forty freelancers who asked for a guide on late invoices, and you offer the chasing tool at the end. Each of them was a person you had a reason to write to. A post on a public feed, which anyone might see, is not that. You did not choose the reader.
Common misunderstanding
Direct does not mean wanted. Emailing a bought list of strangers is still direct marketing, and in the UK and EU marketing emails and texts to individuals generally need prior consent, apart from a narrow exception for existing customers who were given a simple way to opt out. Anyone can ask you to stop at any time. Direct marketing also differs from direct sales: it sends a prepared offer to many chosen people, while direct sales is a one-to-one negotiation.
When to use it
Use it when you know who should hear the offer, and you have a reason they will open it. If you cannot name the people, go back to finding them. A larger send will not invent the reason.