As easy as you can get into me, it is as hard to get out of me. Do you know what am I?

Question

You will know that I am coming
From the jingle of my bell,
But exactly who I am is not an easy thing to tell.

Children, they adore me
for they find me jolly,
but I do not see them when the halls are decked with holly.

My job often leaves me frozen,
I am a man that all should know,
But I do not do business in times of sleet or ice or snow.

I travel much on business,
But no reindeer haul me around,
I do all my traveling firmly on the ground.

I love the time of Christmas,
But that's not my vocational season,
And I assure that is because of a sound economic reason.