And of course, popularity of a celebrity is connected to the popularity of the product with which the celebrity is most often closely associated (TV show, film, musical, etc).   The cast of The Big Bang are more well known and popular than a less well-known TV show.

I personally also believe that the reputation of a celebrity also contributes to their popularity.  Darren has the reputation of going above and beyond for his fans, making time to take pics and sign autographs even when he is busy, making eye contact (trying to make a connection), asking fans how they are doing (showing he cares), just in general being very kind to others because he is a decent, good person.   Also, I'm sure he also is aware of how important these moments will be to people, how sometimes the memory of these moments can carry various individuals through tough times in their lives.




From dailydarrennews:


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ourladyj: Post wedding tea. Spilling. #eloisehastwodads







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dailymiaswier:
andymientus: All Tea, No Shade #eloisehastwodads





This is a cute pic.  Look at Darren.  :amused
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larra-belle:
guskenworthy: Hot tea with these hotties! #eloisehastwodads #highteatime






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michaelarden: #eloisehastwodads






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Michaelarden: Last dance. #Eloisehastwodads








Darren is enjoying London.   It looks like a beautiful, sunny day!
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Via Darren’s Snapchat - August 21, 2016












More pics with fans:



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kathrynashlee: this is up there with one of the best days of my life.  :happy face thank you darren and mia for being so sweet and stopping to chat.  heart





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dailydarrennews:
ohmydaysitshayz: Well this happened.
hannah_hannah_bo_bannah: Gonna cry tbh #darrencriss #london







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Topics tagged under highteatime on Darren Criss Fan Community Tumblr_oc9h9nviw91uetdyxo2_r1_500
dailydarrennews:
@VanessaKuenzle
tbt to last night when I bought @DarrenCriss a tequila shot #glee

@VanessaKuenzle @gleefulIy @DarrenCriss it is…. but this better





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matilde_holmstrup: Me and @annaskriver was so lucky to meet the amazing @darrencriss in Covernt Garden yesterday  :happy face :big grin #london #happy #amazing #love #darrencriss #coverntgarden #travelling #lifeisgood #londonlife





Pics from last years iHeartRadio Music Festival (love their friendship  :happy face ):
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Via iHeartRadio’s Snapchat