I'm a fiction editor at a well-established literary journal, and we run our annual contest through Submishmash as well. Since we get hundreds and hundreds of entries, it helps keep things manageable for several reasons.
1) People can pay through the system and we just get all the income through the single source.
2) Entries can automatically be made blind.
3) It's easy to keep things organized in terms of how many times a piece has been read, which judges liked it, etc.
If a piece is marked as "Received", it means nobody has even clicked it once. As soon as someone looks at it once, even just glances at it, it's marked "In Progress", though that might not actually mean anything depending on the specific situation. Since virtually everyone will be "rejected" (as a status, as far as the system is concerned) it's likely that denials won't happen until the end of a given contest, since you can Accept + Archive the winners, then archive all the losers at once, instead of clicking through menus hundreds of times.
