For the same reason as Kova and Trulli were at Caterham I would expect. A top'ish driver with good technical development skills and marketable value could help drive the team up the grid.

Pic did a good job and was highly impressive throughout 2012, but so did Glock over the past three years and he's not given credit that he deserves. Glock was supposedly given lesser equipment to work with and less than preferential treatment at time by the team, which gave the impression he was slower than he was. But don't forget, once Glock got the update at Spa he was the closely challenger to the Caterham pair.

I never understood why Glock was earning so much money at Marussia.

I never actually understood why did he go there. He could have drove for Lotus F1 today, but he wanted a backarker

I think both Caterham and Marussia have realised that the financial perils of F1 are far greater than they anticipated and - with initially expensive regulations in 2014 - are probably abandoning 2013 for 2014. Why bother paying Kovalainen/Glock for not scoring points when you could get a hell of a lot of money from someone doing a slightly less capable job.

You would think that at some point these teams would learn.