Dive summary: 

• Twitter has signed a multi-year deal with Starcom MediaVest Group (SMG), a unit of Publicis, the third-largest ad holding company in the world. 
• The terms of the deal, estimated to be worth hundreds of millions of dollars, have been vague; it is unclear whether SMG will offer guaranteed ad buys or if it is just an estimate of the value of deals Twitter may receive from SMG clients. 
• SMG did comment that its clients will receive first choice on Twitter ad options.

From the article: 

"In addition, and perhaps more importantly, SMG and Twitter will conduct research together on Twitter's impact on consumers and brands, including a 'social TV lab' to study the relationship between Twitter and TV. 'What we'll be able to do is get better consumer data, trend info and audience segmentation to feed into planning and modeling to make better decisions,' Ms. Desmond said."