Last week the following question was posted on the DevCentral WebAccelerator forum: 

"What benifit would i get with WA module. Is it only doing the caching operation & fasten/increase the performance of application. What it is performing other than that."

The question was answered in the thread  but I thought that this topic could use a more in depth discussion or a series of discussions as this is the question that we are faced with on a regular basis. 

In addition to improved application performance for end users deploying an acceleration solution also provides cost savings and improved uptime. 

Cost Savings

Most users that deploy acceleration devices see costs savings in multiple areas.  Bandwidth is reduced from compression and caching at the browser.  I have heard from some customers that after deploying WebAccelerator they saw their bandwidth usage drop from 400 Mbps to 200 Mbps.  The bandwidth reductions allow customers to delay bandwidth upgrades or use the "newly found" bandwidth for other purposes. 

Once static content is offloaded from the servers the number of requests being processed by the origin servers drops significantly allowing for the same hardware to be used for a longer period of time before additional servers need to be added. 

Improved Uptime

Nobody likes a slow loading web page but what is even worse is downtime.  Application Delivery Controllers can help with directing traffic to only servers that are available or re-directing a response when an error message is received.  WebAccelerator extends that functionality by providing the ability to stand-in and serve expired content.  In my opinion serving stale data is better than serving no data at all. 

Next in the series:  How fast is fast enough?