Google announced this week that it will now offer Product Listing ads to all marketers, enabling them to advertise an entire business inventory while simultaneously offering consumers relevant, quality content.

The ads are displayed to searchers who input queries related to products in an advertiser's Google Merchant Center. The ads don't require keywords or text – they are triggered according to descriptions in the Merchant Center. Instead, they emphasize images.

The efficacy of the ads among early test users should make marketers consider the value of image content in all search marketing campaigns. Google suggests that the visualization of site offerings has led to more clicks, more relevant traffic and higher ROI.

Marketers may be interested in Product Listing Ads, as sneak-peeks of site content can prove relevancy and catch clicks. With the recent launch of Google Instant Previews, relevant content is now more important than ever in attracting Google users to websites.

Instant Previews offer snapshots of webpages that come up in results, and specific search phrases are highlighted. Consumers can now be more discerning about which sites they visit, and marketers must plan content marketing strategies accordingly.