Unless someone from Intuit wants to chime in and give us current figures, there are different ways to estimate the number of businesses using QuickBooks:

In mid-2008, Intuit claimed that QuickBooks had 3.7 million users, representing 94.2% of the business accounting market.

A current Intuit webpage asserts that QuickBooks holds 85% retail market share in small business accounting software.

SCORE says there were an estimated 29.6 million small businesses in America in 2009. How many of them license their own accounting software? Who knows? The vast majority of the ones who do their books in-house, however, have got to be using QuickBooks.

It’s a huge market, and there are thousands of software developers in the Intuit Developer Network who want to reach that install base. These developers can try to get their app listed in the Intuit App Center.

Those select apps have a built-in marketing connection to the user base, at least for users of the 2010 and 2011 versions of QuickBooks. The App Center — located as a button on the QuickBooks icon bar — makes those apps just one click away from the user. Selected add-on developers can also advertise on QuickbooksUsers.com.

How about users in the cloud?  Intuit now claims 215,000 users of its QuickBooks Online Edition, with growth last year of 44%.

Any way you look at it, QuickBooks dominates the SMB accounting software market.

QuickBooks 2010 introduced something new: a suite of optional products/services that integrate into QuickBooks. There have been 3rd party solutions available for QuickBooks for years, but the difference here is that these new products/services live on the web.

They are accessible directly within the QuickBooks application, by clicking on the App Center button. You’ll see the Intuit Workplace App Center.

Almost all of these solutions are available to try for free for a limited time. Then there is a monthly subscription fee if you choose to continue using them.

There are currently three main categories of apps:

1. Professional Services apps. These include document, fax, and expense managers and other efficiency-enhancers for professional offices.

2. Financial Services apps. Add-ins for accountants, tax practioners and financial advisors.

3. Field Service apps. Route and vehicle tracking and more.

There are also project management apps, marketing and CRM apps, management reporting apps, and a nice inventory analysis app.

The suite of available solutions is growing all the time and with it, the possibility of making millions of offices more productive.

I spoke with Brian Sweat of Alterity, Inc. about developing products for the Intuit Workplace App Center. The App Center connects QuickBooks users with a variety of optional software products.

Brian, tell me a little about your background and your company.

I’m the Product Manager at Alterity and have been working on the ACCTivate! product line for the last 9 years.  ACCTivate! is a full-featured inventory and distribution management system designed for QuickBooks® users.  We joined the Intuit Developer Network in 2003 and were in the first group of Gold Developers in 2006.

Alterity just released EZ Analytics for Inventory as a solution within QuickBooks’ App Center. Tell us how that product came to be and what business problems it aims to solve.

The Intuit Partner Platform was launched in late 2008 as a part of Intuit’s  “Connected Services” strategy.  We recognized this was a great opportunity for both Alterity and Intuit.

Advanced inventory management is a common need for many QuickBooks users.  We realize that many users don’t want to switch to a mid-market system for better inventory management.  EZ Analytics for Inventory provides simple tools to better understand their inventory without any changes to their business process.

Your inventory solution is Software-as-a-Service (SaaS). And that seems to be a trend for QuickBooks add-ons starting with the new QuickBooks 2010 versions…user data moving into “the cloud”. What do you think the users’ experience will be like compared to using desktop software?

The experience is great!  You can sign up with just a few clicks using your Intuit account.  Intuit handles the entire sign-up and billing process.   Of course, there’s no software to install and updates are automatic.  The user interface is much more robust than traditional desktop software.

What technical issues did you run into in developing a web-based product that interfaces with QuickBooks? And what is it like supporting a web-based product?

There were a few major changes for us.  First, it required a new set of development tools (ie Adobe Flex Builder).  We also switched from using Microsoft SQL Server to the online Intuit Data Services.  There was definitely a transition for our development team, but we’re really happy with the changes.

Providing end user support is very different as well.  Intuit is responsible for synchronizing and storing the QuickBooks data.  EZ Analytics for Inventory is pretty easy to use, so we really haven’t had much additional support.

On a closing note, it seems to me that for both financial and technological reasons, the App Center approach could be a win-win-win for 3rd party developers, Intuit, and end users. Any final thoughts, Brian, about the QuickBooks App Center?

We completely agree!  We are very excited to see more users and developers discover the Intuit Workplace App Center.  EZ Analytics for Inventory is our first Workplace App and we have big plans for the future.  I really appreciate the opportunity to talk with you.

Thank you, Brian!