Voting power is determined by how much Steem Power (vesting STEEM) your account has AND how active you've been recently voting. Steem blockchain / network approximates your average voting rate to determine your voting power when you post. Calculation looms like this:
SteemPower / VotesPerDay
Since Steem can't predict how many votes you will cast in the each day, the VotesPerDay calculation is a moving average. Meaning each consecutive vote you make increases your average VotesPerDay. Go 24 hrs without voting then your VotesPerDay will reset to the min value: 20.
You can increase your voting power by posting and voting. 50% of all content and curation rewards are paid out as SteemPower.
The amount of benefit a vote confers on the authors of a post depends upon how many votes are already cast. This is because payout is determined by the following calculation:
NewPayout = (OldVotes + NewVotes)^2
This means that small votes have a much greater absolute benefit when added to a post with a lot of votes, and almost no apparent benefit when added to a post with no votes.
InitialPayout 1 = (0+1)^2
AfterSecondVote 4 = (1+1)^2
The outside observer would think that the second voter counted for "3" even though both voters were of the same weight. The reality is that if a 3rd down vote was cast by an another voter of equal weight the Payout would fall to 1. A fourth voter downvoting would return the payout to 0.
