Scott Behrens
Analyst · D.A. Davidson
Thanks, Ralph, and good morning everyone. I’ll be staring my comments on Slide 9 with key takeaways from the quarter. Overall, we had a strong quarterly performance. We saw a solid sales performance and in particular with growth in add-on sales compared to the prior year quarter. 60-month backlog grew $700 million and 12-month backlog grew $160 million. We saw strong revenue quarter starting really with solid growth in our organic business, growing more than 10% or in excess of $10 million over the prior year quarter. The S1 acquisition contributed $22 million of revenue to the quarter and again, that was just for the period February 13 through March 31, so not a full quarter contribution yet.
A key item to point out here, and we’ll continue to do this in the future to help normalize your revenue in your financial models, is that our revenue was impacted this quarter by $4.3 million of deferred revenue haircut. And again that is revenue that would have been recognized in the normal course of business by S1, but was not recognized due to GAAP purchase accounting requirements, so really $4.3 million of pure margin of revenue that we weren't able to recognize. And the final point on this slide is that our monthly recurring revenue represented 66% of the quarter's revenue.
Continuing on Slide 10 with key takeaways from the quarter, the operating expense growth compared to the prior year quarter was almost entirely related to the S1 acquisition as operating expense for our organic business was essentially flat with the prior year. The S1 acquisition contributed about $26 million of operating expenses to the quarter. We also incurred $15 million of acquisition-related onetime expenses. Those costs including severance, change in control, investment bank fees, and other professional fees related to the deal. So, excluding the impact of this $15 million in acquisition related one times, we saw strong growth in operating income and adjusted EBITDA over the prior year quarter, up 79% and 67% respectively. So overall a solid quarterly performance.
And finally on this slide, we ended the quarter with $200 million in cash, we used part of this cash to repurchase stock, about 186,000 shares for around $7 million here to date, and used $3 million of cash for scheduled pay down on our term loan. And we finished the quarter with $367 million of total debt.
Turning now to Slide 11, this is our normal depiction of the ratio of revenue derived from backlog versus that portion of revenue that is derived from current period sales. As you can see, the mix is consistent compared to last year, and just overall, we are very pleased with the recurring revenue coming out of backlog, which is providing us a stable, predictable, and solid base of our revenue stream.
And turning lastly to Slide 12 is still already mentioned, we have achieved $33 million in synergy cost reductions, which is 10% more than our original plan that we laid out in our February earnings call. We still expect to achieve further cost synergies beyond this $33 million of those additional savings coming from both data center and facilities consolidation. At this time, though, we are still assessing those plans and expect to be able to provide the timing and financial impact of those actions at our next earnings call.
We also have a couple of updates here for your financial models on the effects of purchase accounting on our 2012 financial outlook. We had originally expected the deferred revenue haircut to be about $12 million in 2012 with the remaining $8 million of haircut rolling into 2013. We are now expecting the full amount of the haircut to roll into 2012. So, the full $20 million to be dealt in 2012, really the margin effect of this higher deferred revenue haircut in 2012 will be offset by lower expected expenses from other valuation adjustments, including intangible amortization as well as the benefits of the higher cost synergies that we have achieved.
That being said, based on our performance year-to-date and our outlook for the rest of the year, we are comfortable reaffirming the full year guidance that we lay down in our February earnings call, with revenue expected to be in the range of $696 million to $706 million, operating income to be in the range of $99 million to $104 million, and adjusted EBITDA in the range of $165 million to $170 million. And again, both of the earnings metrics exclude the impact of onetime transaction-related expenses.
So that concludes my prepared remarks. Operator, we are ready to open the line for questions at this time.