It has hired direct agency Crayon to handle the activity, which will be backed by press and online ads, and, potentially, a TV campaign.
Workthing will be integrated with The Hotgroup's specialist sites, which include gis-a-job and ASA Group, and will become the company's flagship recruitment site for general jobs.
The site's target audience will range from those in their mid-20s seeking their second job to those at corporate middle-management level.
The site will advertise the potential employer's identity even if an agency is handling the recruitment.
The £6m purchase of Workthing made The Hotgroup the biggest online recruitment company in the UK. It was the latest in a series of acquisitions by the group, which has been purchasing specialist recruitment sites covering sectors such as accountancy and IT.
Workthing was launched by The Guardian in 1999 backed by an adspend of about £30m, but the site failed to live up to expectations after the dotcom boom and in the face of intense competition from companies such as Monster.com and totaljobs.co.uk.
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