Wildfire, which provides software that helps businesses manage their presence on social networks, has a list of clients including Amazon and Sony.
Its expertise will allow Google to understand advertisers’ demands as social advertising threatens its main revenue source, while helping to integrate its own social network Google Plus into other services.
The web giant makes most of its cash from advertising on its search engine but has so far failed to see significant uptake of Google Plus.
Google said the acquisition will create “new opportunities for our clients to engage with people across all social services”. It had previously failed in a bid to buy rival social ad firm Buddy Media, which went to Salesforce.com earlier this year.
Wildfire claims its 400 employees serve 16,000 customers including 30 of the world’s top 50 brands.
Google plans to slot Wildfire into a group of online ad services offered through its DoubleClick business.