I guess Mike Ashley is no longer wanting to sell Necastle then. If you want to sell a club you wouldn't give the manager an 8 year contract as this would put off potential buyers if they wanted to bring their own man in. If he doesn't want to now but something happens a bit further down the line his hands are tied. 8 years is a very long time in football (just think what happened to us in the last 7 years!) and so much can change I am not sure if it i a good thing or not. I guess there are certain get out clauses for both parties such as relegation or England wanting to come in for Pardew etc. Very nice for Pardew though granted.
This will prevent others clubs from taking on Pardew as they would have to pay a lot of compensation otherwise. There is probably a clause so that if he under performs and his contract is terminated they do not have to pay it in full.