What does your payout mean? 
Everyone on Steemit understands that an upvote equals rewards, but what exactly is Steemit promising you everytime someone clicks that thumbs up (
Steemit is paying you a proportion of its daily reward pool. This reward pool is 64 000 Steem dollars per day. This mean a post worth $10 according to Steemit is actually worth 10 SBD. Really brings things into perspective with recent prices, payouts are quite high in dollar terms.
Steemit does not payout all the rewards as SBD, but does a conversion.
Understanding that SBD is an IOU 
SBD is literally an IOU issued by Steemit to pay out posts. The reason is that in most cases there is not enough STEEM produced daily to pay out all rewards. Steemit tries to immediately convert 62.5% of the payout in STEEM as an initial promise, but it does not always have enough STEEM. In these cases you will see a higher percentage of your posts being paid out in SBD.
The Steem Feed
The definition of the feed prices from the Steemit FAQ is,
The price feed is the median price feed of the last 3.5 days of all the top 20 witnesses price feed
A witness has the ability to set the price feed to a % above or below the observed market price. It also takes a few days for any changes to pull through, but theoretically they can set it to anything.
To understand how the Steem feed is used to value your posts in both SBD and STEEM please visit my other post on it here.
Hope it clears up some background to Steemit :)
If you feel this helped you please upvote and/or comment,
Tinus
** Images courtesy of