In the realm of business and commerce, 'scalability' is a revered term broadly utilized to detail the capability of a system to manage an increasing amount of workload or its potential to be enlarged in order to accommodate that growth. Simply put, if a business is scalable, it can handle an increase in sales, workload, and overall growth without straining its resources or compromising its performance.

'Scalability' is not a one-size-fits-all concept; it varies with the type and model of a business. In this context, let's understand scalability in relation to marketplaces.

Marketplaces, physical or virtual, serve as platforms where buyers and sellers come together for commercial exchanges. Companies like Amazon and eBay are prime examples of online marketplaces. The scalability of a marketplace can be determined by its ability to host a growing number of buyers and sellers, accommodate more transactions, or expand its offerings without compromising the user experience or operational efficiency.

When we talk about the scalability of a marketplace, it is often broken down into two distinct types:

1. Vertical Scalability: Also known as "scaling up," this form of scalability involves adding more power to the existing system. For a marketplace, this could look like enhancing the server capacity or integrating robust tools to manage increased transactions.

Example: expanding the platform's server capacity to accommodate an unexpected influx of new users.

2. Horizontal Scalability: Alternatively known as "scaling out," horizontal scalability involves the increase in system components. For a marketplace, this could mean expanding the platform reach to new geographical locations or adding new product categories.

Example: launching the marketplace platform in a new country or adding new product categories such as electronics, apparel, etc.

Scalability is crucial for maintaining the stability, speed, and performance of the marketplace, even during peak times. It supports growth, allows for flexibility, and enhances customers’ shopping experiences.

To sum up, scalability is like the lifeline for marketplaces. As the marketplace grows, so must its infrastructure and capabilities. So when architecting a marketplace, consider scalability from the outset. This foresightedness will surely pay off in the long run, ensuring that the marketplace can easily adapt to support not only its growth but also its long-term success. This glossary article on scalability in marketplaces is an elementary step for businesses to understand and implement in the journey towards high business growth and customer satisfaction.