Over the years we’ve evangelized the need to pay attention to third-party web components. These components can be content delivery networks, web analytics, ratings and reviews, tracking pixels or else anything else not developed by you or that comes from outside your firewall.

There has been an important shift in how web applications are delivered — that shift is to the browser. Previously, the browser did little more than render the instructed graphics; today, however, the browser is actually assembling the web application on the fly from a number of components delivered to it from an assortment of locations.

So how profound a shift is this? When we looked at 3,000 companies and 30,000 distinct transactions and workflows we discovered that it takes an average of 8 hosts to complete a successful transaction. This means that eight different hosts have to deliver content, and the browser has to assemble them in order for a user to make a plane reservation, buy a television or download an iPhone app. (As an aside, we will soon launch the first Gomez Performance Monitor report that provides impartial data-driven insights like this one).

The application is what the user sees, not what the developer creates. There is an entire chain of events that occurs between the application behind your firewall and the browser (what the customer sees). This is referred to as the application delivery chain (ADC). While it is important to understand the dependencies along the entire chain, you need to understand how your choice of hosts and services impacts the user.

This week Akamai experienced a service disruption that lasted for only a few hours, but the impact was measurable across many industries that we measure captured in the chart below.

More and more, applications will only perform when all the parts work in concert. In order to understand the health and performance of an application, it has become more critical to have broad visibility into the health of all the components that make up the application, whether they are inside the data center, delivered from a 3rd party provider, or running within the end-user’s machine, device, or browser.Managing application performance, especially of mission critical applications and their physical and virtual infrastructures, is more difficult than ever. The increasing complexity of application infrastructures is partly to blame. Processing is becoming distributed, occurring within the data center in physical, virtual, and hybrid environments; in shared 3rd party environments delivering specialized outsourced components; and on the increasingly more powerful end-user clients.

Third-party components enrich your website’s functionality to drive more traffic to your site, offer interactive experiences, increase conversion, and add new functionality when it becomes available. However, your website can be vulnerable to degraded performance or a complete shutdown if any one of these components fails.

To learn more about how to mitigate the performance risks of third-party web components, join Forrester’s Mike Gualtieri and Compuware CTO Steve Tack for a webcast on August 30 at 1:00 ET