The unemployed history graduate used the board to proclaim his availability for work, offering to work his first month for free.
In his five days walking around the capital last month he attracted widespread media coverage and generated 250 enquiries from interested employers.
He was also spotted in Fleet Street by JCDecaux's managing director Spencer Berwin and is now a junior sales co-ordinator at the outdoor media owner, working in the billboards, street furniture and StreetTalk phone boxes team.
The company also declined Rowe's offer to go through his first month unpaid.
Berwin said: "I was very impressed by David turning himself into a human billboard -- he's displayed a natural talent for outdoor advertising.
"His sales pitch showed enormous confidence and a determination to succeed that is highly attractive for any employer."