It's not necessarily their success, although the new Liverpool boss appears to be building something promising, while West Ham United's manager has done a brilliant job - a couple of forgettable results aside.
It's the charisma the two have brought to their roles.
Indeed, simply by using their personality, they have given both their fans and players huge lifts.
While Sam Allardyce was at West Ham and Brendan Rodgers at Liverpool, both clubs suffered a serious downturn in atmosphere. Big Sam appeared to know he was leaving at the end of last season so essentially packed his bags early. The Hammers went on a torrid run of form and fans looked as though they just didn't want to be at Upton Park.
Under Rodgers, despite the highs he achieved with the Reds when Luis Suarez was at Anfield, there was simply no joy anymore.
Liverpool's results and lack of tempo on the pitch had managed an impossible feat: to silence their famous home atmosphere.
And yet look at both clubs now. Bilic's charisma shines through in his West Ham press conferences and he's got his team playing with personality, too.
The same can be said for Klopp and even more so, with the German already having won the hearts and minds of many in English football.
It's not about a flowery style of play but it's about fight and passion. Both possess it and both can clearly communicate it to players and reporters. In that sense, they've taught a valuable lesson to the rest of the Premier League: modern football isn't a place for robotic 'philosophy' or buzzwords. A man who can motivate and captivate is still one of the game's most powerful weapons.