YouTube is in a heated battle to retain some of its top video stars as competitors including Facebook and Vessel are recruiting them for their respective services.

Sources familiar with the matter told The Wall Street Journal that the Google-owned company is offering some of its top content creators performance bonuses to go along with multi-year contracts. The bonuses may be doled out based on how many hits a video gets, for example.

Under such deals, videos would remain a YouTube exclusive for a set length of time before they could be republished elsewhere.  

Vessel, a startup founded by former Hulu CEO Jason Kilar, is said to pose the biggest threat to YouTube. The video subscription service is expected to launch by the end of the year and has been aggressively targeting some of YouTube's top talent. Having already raised $75 million in venture capital, the startup certainly has enough funding to attract quality content creators.

One YouTuber that wished to remain anonymous told the publication he/she would like to stay with YouTube but some of the competing offers are incredibly attractive.

In addition to monetary benefits, Vessel is pitching people on the idea that their content won't run alongside low-budget clips like on YouTube. And much like YouTube, Vessel wants exclusive rights to content - up to three days - before it can be published elsewhere.

Vessel is likely to steal away at least some of YouTube's top stars before it's all said and done. What'll be interesting to see is how quickly these draws can rebuild their following on a brand new service after having promoted their brand on YouTube for years.