Popularity and perception are very influential...why else would people fight each other to the death and be willing to pay hundreds of dollars over a Tickle Me Elmo. at Christmas...when it can be bought at ANY other time of the year for less than $30!!!
Well, one of my resolutions is also to blog more often!
However, I don't like to consider things 'New Year's Resolutions', otherwise I feel like I won't keep them! :) Maybe I should just call them 'goals' for the near future!
You make a good point and ask a good question. I don't have the answer. However, I will say...StumbleUpon is bringing people to your site that would normally never be there...and as stated above, if your site is good, you might get some unexpected subscribers out of it.