Have you ever wondered what witnesses make?
STEEM witnesses are the secret sauce that make Steemit function. Every post you submit, transfer you send, and vote you cast are processed by the witnesses. Being a witness is a big responsibility, and the equipment and maintenance can be expensive and time-intensive. Because of this, witnesses are compensated with SP for every "block" of transactions that they process.
The blockchain, through the witnesses, processes 21 blocks of transactions in each 63-second round. The top 19 witnesses get 1 block every round, with the other 2 blocks being distributed among the other active witnesses according to their ranking.
We want to emphasize that witness rewards do not come from the reward pool. As new tokens are created, a certain percentage is distributed to authors and curators, while the witness rewards are distributed from another percentage. They are two separate pots.
We run a script every week that analyzes every block processed in the previous week to calculate what each witness earned that week. This post was put together using data pulled from 
Vitals
STEEM/USD Conversion Rate at time of analysis: $2.37/STEEM
Dates covered by analysis: May 21st - May 27th, 2018
Bar Chart
This bar chart shows the distribution of SP earned by witnesses over the last week.
As you can see, the earnings drop off significantly for those that aren't in the top 20. This is due to the fact that the top 20 witnesses handle the bulk of the transactions that occur on the STEEM blockchain. Because of this, their overhead is significantly higher, especially as the blockchain continues to grow.
Pie Charts
We have reorganized our pie chart visualizations into earning tiers. This will allow a much clearer picture of the way earnings are distributed to the various witnesses.
Tier 1: Top 20
Tier 2: 21-40
Tier 3: 41-60
Tier 4: 61-80
Tier 5: 81-100
Tier 6: Under 100
Full Table
Here is the full table of results, this totals all witness earnings in SP and the USD equivalent over the last week, sorted by each witness' ranking.
