Short Answer ( Sean-king) and (cloh76):
Some upvotes are worth more than others. It depends upon how much Steem Power the voter has. If they have little or no Steem Power, then their upvote isn't worth even a penny.
To my knowledge it depends on how much steep power the people who reply or upvote you have. The more they have, the more influence and rewards you get. My up-vote will not be worth anything since I am still new as well and have very little steam power
More In Depth Answer (teatree):
Basically it depends on the Steem Power of the person doing the voting. A minnow with less than 100 steem power will only be able to give you a fraction of a penny. Someone with about 1000 steem power will be able to give you about 5 cents. Someone with 2500 steem power will be able to give you 9 cents. Someone with 100,000 steem power will be able to give you a few dollars. The "whales" have millions in steempower, which is why a single vote from them can be worth as much as $50.
The key to this is to try to write well-constructed interesting posts, with images and a good title, and then you may be able to catch the eye of an upvoter who can give you real money.
Be Sure To Thank Them By Giving Them An Up-Vote In The Comments