Tetra Marketing is a personal essay newsletter on online marketing trends, entrepreneurship and the psychology of modern life. Recent issues cover how marketing tactics get copied until they fail, the case for setting an exit number before selling a business, and the procrastination mindset behind big goals.

A Dutch knowledge base on AI visibility for knowledge-intensive small businesses, covering how to measure visitors arriving from ChatGPT, Perplexity and Gemini, local SEO in the age of AI assistants, and why no provider can guarantee positions in AI answers. The writing is practical and carefully argued, with concrete steps and an honest view of what can and cannot be promised.

A solo marketer writes about navigating online marketing and Big Tech while holding progressive values, covering topics like forced AI features in software and building sustainable business habits. Readers get candid, personal takes on tool choices, social media practice and critiques of tech company behaviour.

Mario Armenta shares practical advice on building, scaling and selling online businesses, drawing on his own experience. The issues argue for selling digital businesses early to lock in liquidity, and explore regional pricing and marketing in Latin America.