The document provides guidance on when to use web, apps, bots, and agents from a marketing perspective. It recommends using the web when ubiquity, speed, information delivery, or existing infrastructure can be leveraged. It suggests using apps when context, engagement, accessibility from a single source, or rich interactivity are important. Bots should be used when existing customers or large audiences need service or attention. Agents are best utilized when integrating with other platforms, differentiating on those platforms, voice is sufficient, existing payment solutions apply, or simplicity is key.