Twitter is to start selling pre-roll video ads ahead of Periscope videos in a move to make a little more money from its service.

Selected publishers and creators can earn from the ads and get around 70% of the revenue from the ads.
[blog.twitter.com...]

Interestingly, twitter describes the advertising as "brand-safe" which is probably a reflection of the turmoil caused recently by advertising appearing against inappropriate content on Google's network. [webmasterworld.com]