How to get LinkedIn Premium for free?

Does anyone know how to use linkedin Premium for free? Like creating a new account and then using the 1 month free trial.
Can I use the same card details in all accounts?

LinkedIn is offering 3 months and 6 months of free access to LinkedIn Premium subscription for Visual Studio Annual subscribers. Anyone subscribing either of Visual Studio Enterprise, Visual Studio Professional, Visual Studio Test Professional or, MSDN Platform can enjoy this free LinkedIn Premium benefit.

If you subscribed to a premium subscription of LinkedIn and received the 1-month free trial offer, typically LinkedIn will not let you have the same subscription type for free again. You may be able to subscribe to a different level of premium for the free 1-month trial offer.

Set-up your LinkedIn profile pretty and you shall have an option to go for LinkedIn premium.

They also email you after sometime to go for another trial for a different subscription as well.