IntoNow’s app technology scans the sound on TV programmes to automatically identify what show a user is watching, which can then be shared on Facebook, Twitter, iTunes and Netflix.
Yahoo’s investment will help expand the IntoNow app onto different platforms beyond the iPhone and desktop computer, including the iPad and Android devices. The app launched just 12 weeks ago.
The media company is aiming to become a content provider as its looks to turnaround declining search revenues.
The web company reported profits of $223m (£137m) for the first three months of 2011, down 28% on the same period the previous year. Like for like revenue also fell 6% to $1.06bn (£644m).
The financial terms of the deal have not been disclosed, although Yahoo is reported to have spent between $20m (£12.1m) and $30m (£18.2m) on the acquisition.