Google is preparing to reduce the number of ways that marketers can purchase ads on YouTube, with the aim of encouraging advertisers to make use of its ad buying software.

By the end of 2015, marketers will no longer be able to use the DoubleClick Ad Exchange, Googles automated digital ad exchange to buy YouTube ads.

Instead, ads will have to be purchased either directly through Googles sales force, or through two different platforms: Google AdWords, the same tool used by many marketers to buy search ads, or DoubleClick Bid Manager, a software platform that enables more automated ad buying.

The move limits the ability of advertisers to use their own software to purchase YouTube ads, in theoretically reducing the amount of control, visibility and access to data that brands will have, and will be seen by many as Google leveraging its size and power to force unpopular changes on advertisers.

“To continue improving the YouTube advertising experience for as many of our clients as possible, well be focusing our future development efforts on the formats and channels used by most of our partners,” said Neal Mohan, vice president of display & video advertising at Google. “With this change, well be able to invest even more in creating the best and most effective YouTube advertising and buying experiences possible.

“Video advertising and programmatic buying are growing rapidly and being focused in our investments will help us drive them forward at an even faster rate.”