estimates and changes to these estimates will cause the fair values of our stock awards and related stock-based compensation expense that we record to vary.

We record deferred tax assets for stock-based compensation awards that result in deductions on our income tax returns, based on the amount of stock-based compensation recognized and the fair values attributable to the vested portion of stock awards assumed in connection with a business combination, at the statutory tax rate in the jurisdiction in which we will receive a tax deduction. Because the deferred tax assets we record are based upon the stock-based compensation expenses in a particular jurisdiction, the aforementioned inputs that affect the fair values of our stock awards may also indirectly affect our income tax expense. In addition, differences between the deferred tax assets recognized for financial reporting purposes and the actual tax deduction reported on our income tax returns are recorded in additional paid-in capital. If the tax deduction is less than the deferred tax asset, the calculated shortfall reduces our pool of excess tax benefits. If the pool of excess tax benefits is reduced to zero, then subsequent shortfalls would increase our income tax expense.

To the extent we change the terms of our employee stock-based compensation programs, experience market volatility in the pricing of our common stock that increases the implied volatility calculation of publicly traded options in our stock, refine different assumptions in future periods such as forfeiture rates that differ from our current estimates, or assume stock awards from acquired companies that are different in nature than our stock award arrangements, among other potential impacts, the stock-based compensation expense that we record in future periods and the tax benefits that we realize may differ significantly from what we have recorded in previous reporting periods.

Results of Operations

Impact of Acquisitions

The comparability of our operating results in fiscal 2014 compared to fiscal 2013 is impacted by our acquisitions, primarily our acquisitions of Responsys in the third quarter of fiscal 2014, Tekelec in the first quarter of fiscal 2014 and Acme Packet in the fourth quarter of fiscal 2013.

The comparability of our operating results in fiscal 2013 compared to fiscal 2012 is impacted by our acquisitions, primarily our acquisitions of Acme Packet in the fourth quarter of fiscal 2013, Taleo Corporation (Taleo) in the fourth quarter of fiscal 2012 and RightNow Technologies, Inc. (RightNow) during the third quarter of fiscal 2012.

In our discussion of changes in our results of operations from fiscal 2014 compared to fiscal 2013 and fiscal 2013 compared to fiscal 2012, we may qualitatively disclose the impacts of our acquired products (for the one year period subsequent to the acquisition date) to the growth in our new software licenses revenues, cloud SaaS and PaaS revenues, software license updates and product support revenues, hardware systems products revenues and hardware systems support revenues where such qualitative discussions would be meaningful for an understanding of the factors that