Search retargeting uses aggregate search data to serve banner advertising across the network of advertiser sites and has the benefit of being able to target more specifically than other forms of behavioural targeting, such as 'ad retargeting' which is based on a user's visit to an advertiser's website, rather than specific pages. Being able to track data beyond the home page of a site means that the creative on the display advertising can be adjusted based on the keyword or keyword group a user previously queried.
The number of display ads can be based on an advertiser's keyword portfolio and reflects the type of dynamic advert keyword targeting used in PPC campaigns, but adding a higher level of creative implementation. However, a big inventory of search terms can make a campaign very unwieldy but the system is scalable and advertisers need to test the effectiveness of different approaches.
24/7 Real Media say that although any advertiser can take advantage of search retargeting, the approach best serves retailers who can make their banner advertising more targeted and therefore effective, with higher clickthrough and conversion rates being reported, which also reflects the importance of online search behaviour to identify user behaviour and needs.