Excluding the temporary impact on our entertainment research business, our consumer insights business grew 4%. Performance media and data reported $72 million in net revenue, an increase of 11% year-over-year. The strong growth was driven by increased spend in the transportation and travel vertical, which continues to recover from the pandemic. Performance media has been a standout performer in 2023 despite a challenging macroenvironment, posting positive year-over-year growth each quarter. Creativity and communications delivered $244 million in net revenue in the third quarter, a year-over-year increase of $1 million. Excluding advocacy, net revenue increased $6 million or 3%. This marks a return to positive growth for the capability and continues a trend of sequential improvement throughout 2023.
Stagwell Marketing Cloud group delivered more than $47 million in net revenue in the third quarter, representing a 20% increase over the prior comparable period. $36 million of this net revenue came from our advanced media platforms group and approximately $11 million was derived from our software platform products. In the third quarter, we ramped up our investment spending in the Stagwell Marketing Cloud by $6.4 million over the prior period as we drive to deliver a suite of self-service products to our clients, enabling them to perform a host of marketing communication activities inhouse. Now moving to operating expenses and profitability. We have continued to take decisive action to manage costs as the pressures we have previously discussed persisted.
Our actions have enabled us to drive our Q3 adjusted EBITDA margins to approximately 19%, back in line with our targeted range of 19% to 20%. I wanted to take a moment to discuss the more impactful items here. Staffing, our greatest single cost, was the primary focus of our effort. Beginning in Q1, we took steps to reduce our staffing costs as a percentage of net revenue. We have now successfully reduced the staff cost ratio to 63.4% from 67% at the end of the first quarter, an improvement of 360 basis points. As previously announced, we took action to eliminate $48 million of annualized staffing cost in the first half of the year. Since July, we have taken further actions amounting to an additional $34 million of annualized savings, bringing our total annualized cost savings to $82 million.
Our headcount is now about 7% lower than at the beginning of the year. We will continue to monitor our staffing levels to ensure a strong finish to 2023. We continue to make good progress towards realizing the $30 million of annualized cost savings from synergies announced at the time of the merger. With the implementation of our global ERP and HR systems nearly complete, in Q3, we began to consolidate our agency’s finance organizations to our shared services platform. Based on actions taken thus far, more than $1 million of annualized savings is anticipated. We expect to continue implementing this consolidation across our remaining brands, leading to further cost savings. As part of our plans to consolidate our real estate footprint to reduce costs and increase collaboration, we have realized more than $2.5 million of annualized savings this year to date, led by consolidation efforts in both London and New York.
As a result, we delivered $102 million of adjusted EBITDA in the quarter, representing a 19% adjusted EBITDA to net revenue margin, and paving the way to restoring our adjusted EBITDA margin, 19% to [indiscernible], in line with our previous comments. As I previously noted, despite the tough macroenvironment, we have increased front spending in the cloud by $6.4 million year-over-year. Adjusting for this strategic investment, our adjusted EBITDA margin would have increased by an additional 140 basis points to 20.4%. Now moving to the balance sheet, we continue to take actions to improve the strength of the long term financial position. Starting with deferred acquisition consideration, we reduced obligations by approximately $28 million from year-end to $134 million at the end of Q3.
