Twitter is continuing its office expansion in the US, today announcing that it has opened a new office in Detroit’s growing technology district focusing on boosting the company’s interaction with marketing and advertising in the area to push its Promoted Products service.

The new office will be based in the M@dison Building, owned by Rock Ventures, which is part of a portfolio of companies owned by Quicken Loans founder and Cleveland Cavaliers owner Dan Gilbert.

Bedrock Real Estate Services brokered Twitter’s company’s lease, tempting them to establish a presence in the area. In the last 18 months, have helped nearly 40 new-economy companies find a home in downtown Detroit.

The Detroit office is Twitter’s newest regional sales office, with the company having already established a base in Washington DC, Cincinnati, Austin and Atlanta. The company says that its regional offices “supplement” its larger presences in Chicago, New York, Tokyo, London and Dublin, “allowing staff to work closely with marketers on campaigns using Twitter’s Promoted Products suite of advertising products.”

Yesterday, we reported that Twitter was hiring in both London and Dublin, as it looked to expand its operations in the UK, Ireland, The Netherlands and Spain.

Twitter joins other sartups in the area including app development company Detroit Labs, CAPTCHA pioneers Are You a Human and UpTo, creators of a new social calendar service.

“Twitter coming downtown is exactly the kind of innovative company Detroit needs to advance our vision of becoming one of the most exciting high-tech and web-centered corridors of growth and activity found anywhere,” said Gilbert, Chairman of Rock Ventures and Quicken Loans, and Majority Owner of the NBA’s Cleveland Cavaliers.

“Twitter chose Detroit because of the city’s growing, young and energetic environment. This is further proof that the country is starting to wake up and take notice – if you want to create a thriving, growing tech business, downtown Detroit is one of the best places to be,” Gilbert added.