Platform Mechanisms

Becoming a platform is, first and foremost, a mindset and cultural shift within an organization.Instead of selling to a market, platforms host a market. Instead of selling a wine, platforms manage a bar.
Going from selling products and services to managing a platform is common, because most platforms started by gaining significant market positions selling products and services. Why? Because platforms must attract enough participants to achieve a Critical Mass, and they usually only do so if the organization is already a central part of a market.
Starting a platform from scratch with no central market position is a fool's errand, while some have succeeded the vast majority did not live to tell the tale. Alternately, transitioning from a market leader to a platform has become a common ambition of notable organizations. There are now playbooks and examples to learn from. The transition is still full of challenges that befuddle even the best business leaders.
Platforms have counter-intuitive design challenges: generally, the most valuable features and capabilities are geared towards attracting and retaining activity between participants -- and a good majority of them are features either no one wants, everyone tries to game, everyone hates, or no one notices. Similar design challenges are likely found in the role of a school headmaster.
Yet, to become a platform is to create, curate and manage an ecosystem of participants -- to facilitate a hub of market activity. More simply, they must be a conduit for sellers to reach buyers, and buyers to discover and compare sellers; or, providers to be found by seekers, and seekers to find providers.
So, the transition to platform runs contrary to the organizational trajectory that won a market leadership position. Rather than directly addressing the needs and wants of a customer, platforms must be thorough in developing and maintaining trust within and among participants.
Perhaps even more contrary to a market leaders culture is the transition from tight control to barely managed chaos. To become a platform, organizations must let go of some of their vigilance: protecting customers, controlling market share, and upholding the highest quality standards are instincts that will cause discomfort as platforms get off the ground. At their best, platforms often start as barely managed chaos.
The growth from market leader to platform is to institutionalize the following: to better serve the market, let the unknown come and the unexpected occur. Platforms tend to be more successful if they design for and uphold principles of Emergent Innovation, allowing more or less anyone and any organization to at least try to gain platform access. It's a Come one, come all policy.
The way to best serve customers changes from directly serving them to letting others try, and to create clear, strong, and stable Platform Mechanisms.

Common Features of a Technology Platform

Technology-based Platform Methods

Leading technology companies offer a suite of tools to develop on their platforms, typically called an Software Development Kit or SDK. This includes not just Microsoft, Apple and Android, but also Nvidia and other hardware providers.

Developer Community Hub

Ease of Getting Started

Most of the platforms have an obsessive focus on helping people and organizations get started.

Let them find bugs for you:

Let them build for you.

This is often, but not always, accompanied by an App Store.

Unlimited Functionality atop Core Functionality

A modern Application Programming Interface or API. This is most often coupled with Plug ins, Add ons, Extensions offered through a catalog or marketplace,
Web Browsers also use Plug ins, Add ons, Extensions, here is an example:

Data that Moves

Web Applications often have a slightly different way they become a platform -- they focus on fluid data mobility between their service and other services through applying conventions, such as the REST API, and use Web Standards for authentication and security.
Airtable also sports a less common, but extremely helpful, personalized set of Documentation that allows you to follow the docs with your own data model.
Thus, instead of having an App Store or an Extension library, they have an Integration Library, that often include One Click Integrations.

Unlimited Content or Options

Input Markets, or a marketplace of content or tools that can facilitate a user finding and utilizing what they might be looking for. For example, web-based video editors now offer a marketplace of stock video footage, stock music for a soundtrack, in addition to the video editing tools. In many ways, this can be thought of as a Content Marketplace.

Promotion Mechanics

Very Often: Open Source, using GitHub as a primary distribution platform to early adopters.