There are mashups and then there are mashups, as I'm finding out. However, if you're looking for a clean definition of a mashup, here's WikiPedia's:

"A mashup is a Web site or application that combines content from more than one source into an integrated experience."

What has occurred is that public Web APIs, such as those stood up by the likes of Google, are allowing savvy developers to take content and behavior from one SaaS and mash it together with another, thus forming a new application custom-made to solve the business problems of the end user.

Since there is plenty written about mashups I won't dwell on them here. However, the number and level of sophistication of mashups have grown exponentially in the last several months, and this trend will only continue. This could be the next great thing that happens to the world of SaaS, and a new way to sell the value of SaaS. Here's why.Let's face it. While you love the way your SaaS app does sales management, you may hate the way that same SaaS app does accounting. Furthermore, let's say you are looking for an integrated mapping system, perhaps one that displays delivery and sales routes, and does so with the current traffic report. However, you can't have it all… or can you?

Considering that mashups are really ad-hoc applications that combine the value of many applications, typically Web-delivered, the logical progression of this approach is to mashup SaaS apps, perhaps many SaaS apps, into something that's exactly what you're looking for. In other words, sales management from SaaS app 1, accounting services from SaaS app 2, and both mashed with the Google mapping API to provide mapping functionality. Kind of like building a custom car using Ford for the engine and transmission, GM for the body, and BMW for the electronics.

However, most SaaS players did not build their offerings with mashups in mind, and while it's possible to do rudimentary things, such as adding windows to the user interfaces, well-integrated applications are not yet possible, generally speaking. Or, as the kids say it, they are not yet "mashable."

The lack of mashability is due to the fact that they have not taken the time to expose the API, as Google, Yahoo and AOL are doing these days, with the notion of mashups in mind. Also, most SaaS players have not accepted the fact that end users are looking to mash their applications with other SaaS apps (or with internal applications, for that matter), and have pricing models to support it. It's doubtful that a company will subscribe to three or four SaaS players to get at the services and information they need for a mashup, but demand could soon change that price model.

Salesforce's Apex Connect leads the way in providing such API services and is actually a platform unto itself, with NetSuite and Right Now close behind. Indeed, the use of an API to access SaaS services could be the largest growth area for these subscription-based services as organizations seek to integrate these APIs within their SOAs, and use them within mashups going forward. If that happens, the SaaS players will have to rethink how they deliver their value; that they may only be part of a solution, and not a solution unto themselves. The end result could be rapid expansion as end users find it easier to justify the use of SaaS, since the end product is much more solutions-oriented.Public Web APIs, such as those stood up by the likes of Google, let savvy developers take content and behavior from one SaaS and mash it together with another, thus forming a new custom application... The number and level of sophistication of mashups have grown... and this could be a new way to sell the value of SaaS. Here's why.