A01 chaf6542 06 se fm indd

(iv)  Enabling rating of content and online services – for example social commerce on 

e-retail sites.

(v)  Ad funding of neutral sites – web services such as Google GMail

™

 and many blogs are 

based on contextual advertising such as Google AdSense

™

.

(vi)  Data exchange between sites through  XML-  based data standards. RSS is based on XML, 

but has relatively little semantic mark-up to describe the content. Data can also be 

exchanged through standard 

microformats

 such as hCalendar and hReview which are 

used to incorporate data from other sites into the Google listings (see 

www.microfor‑

mats.org

 for details). New classes of content can also be defined and