Last week Google announced that it will now enable advertisers to "nominate" specific text for sitelink descriptions within their Adwords account, controlling the descriptions that display when the Enhanced Campaign Sitelinks are triggered and displayed.
Back in February of last year (2012), Google began enabling advertisers to use text from other ads in their account to create sitelinks with addition detail, but this improvement should help prospective buyers even more by allowing merchants to offer up additional product details and information.
In its own testing, Google users reported that sitelinks with addition detail were more useful and relevant, and click-through rates were much higher than for the same ad with the traditional 2 and 3 line sitelinks.
The new sitelinks format is only available for advertisers using enhanced campaigns - which consequently, need to be updated by July 22nd of this year (2013). After upgrading, advertisers will then have the option to include extra text for their sitelinks.