Earlier this week, The Next Web covered HootSuite’s achievement of reaching the 2 million user milestone. Considering that the Vancouver-based company has stood the test of time while other social media and Twitter clients have either sold out or bowed out, this is a remarkable accomplishment. But there’s a lot more to HootSuite’s success than just being a great Twitter client; HootSuite’s rise is a testament to how a great idea that stays the course can reach great heights. And the heights it has reached compares with that of some pretty stellar companies that are also part of the software-as-a-service/freemium business realm.

HootSuite has seen growth to date that is on a similar trajectory to the widely popular Evernote, Yammer and Dropbox. The data below outlining Evernote’s, Yammer’s and HootSuite’s rise to 2 million users illustrates that there is significant market success of SaaS tools and Freemium business models.

growth 2mil hootsuite 520x300 HootSuite: A software as a service success story

Evernote and Dropbox have continued to grow rapidly after the 2 million user mark, and HootSutie shows definite signs of trending in the same manner. International growth is a key contributor to HootSuite’s user base, having sped this via community building, outreach and crowd-sourced translation.

HootSuite’s reach and trends (courtesy of Alexa) also rank with that of the aforementioned companies, as well as Dropbox and SalesForce, other examples of business using the SaaS and Freemium models:

alexa us global hootsuite chart 520x321 HootSuite: A software as a service success story

alexa hootsuite HootSuite: A software as a service success story

Also worth noting is the relative growth rate of users on each of these services:

HootSuite beta Launch: December 2009
HootSuite 1 Million: November 2010
HootSuite 2 Million: June 2011

Evernote Launch: June 2008
Evernote 1 Million: May 2009
Evernote 2 Million: December 2009

Yammer Launch: September 2008
Yammer 1 Million: July 2010
Yammer 2 Million: Feb 2011

Dropbox Launch: April 2008
Dropbox 1 Million: May 2009
Dropbox 2 Million: Sept 2009

While the data clearly shows that SaaS and Freemium models are fast becoming a widely used solution for many users, it also foreshadows something for HootSuite in particular: it may be the only third-party social media client left standing in the future because of how it has done — and continues to do — business.