• by Laurie Sullivan  @lauriesullivan, December 11, 2017

Global online advertising revenue growth reached 29.6% in third-quarter 2017, after remaining between 23% and 26% year-over-year during the past six quarters, according to data released Monday.

Forrester’s Digital Marketing tracker provides marketers with a quarterly update of online advertising revenue trends globally. The tracker captures revenue and user data for 13 key digital media and services companies, which in aggregate makes up more than 75% of the online advertising market.

Google managed to shake off its challenges, contributing the most to market growth, Brandon Verblow, associate forecast analyst within Forrester Research's Marketing & Strategy ForecastView team, cited in the report.

Verblow said in the report that Google contributed an additional $4.2 billion in spending compared with a year ago -- about 40% of the $10.5 billion growth in spending across all 13 firms.

With a 21.4% growth rate YoY, Google's advertising was the fasting-growing in about six quarters, even as the company dealt with the challenges of YouTube. In third-quarter 2017, YouTube saw the number of brands placing ads programmatically come roaring back, although the number of brands buying programmatically on the platform dipped 17% in April.

Facebook's advertising grew 48.8%, up from 46.9% in Q2 2017. Facebook did top out of inventory, as the company expected, but was offset by better pricing. Forrester suggests that continued improvements in targeting continue to help deliver downstream results. And marketers are willing to pay.

Baidu’s quarterly growth has been on life support -- declining at 6.5% each quarter, reports Forrester, since its healthcare scare in second-quarter 2016. Increased Chinese government regulation of healthcare-related ads on search platforms starting in May 2016, contributed to the decline. In third-quarter 2017, that changed, with growth of 22%.