I have about 100 (give or take 10) submissions on CC and - at last check - around an 80% sale rate. I am the type of writer that writes it and submits it immediately, with little self-editing. I think this is a carry-over from writing through a different site, where everything about the submission was tightly controlled by the buyer and the site itself. The following attributes of the submission were dictated by the client:
- word count
- keywords required & density for those keywords
- title of submission
- writing style/tone (1st person, formal, etc.)
- deadline (usually 24-48 hours)
If a submission did not meet those requirements, it could not be submitted. This sort of forces a writer to automatically self-edit as he/she goes along, because time is very much "of the essence."
I rarely (thank goodness) have rejections by CC for submissions, and the few I can remember are:
- use of an ampersand (in the title, which was included in the body)
- length (too long)
- sentences needed breaks (I can write looooong sentences)
The "too long" rejection was surprising - it was a first and just happened a week or so ago. I deleted a few hundred words and resubmitted with no problems.
The "ampersand" rejection was politely disputed from my end, because the ampersand was in the title which was included at the beginning of the body, as per instructions. Also, I had checked accepted content and noticed a great deal of approved work with ampersands in the title (and elsewhere in the content). I guess I just got the one editor that was a stickler about ampersands. Changed it to an "and" - resubmitted with no problems.
A lot of rejections or rejections for vagueness, ambiguity, wordiness, etc. - from the 3-year stint at "the other site" (as editor for 1 year AND writer for all 3 years), this means your work is far from polished and professional. Clients/buyers want polished and professional. I saw some pretty horrid writing as an editor, to be honest, and I was amazed that those writers got any work at all.
Because Google has placed an "emphasis" on longer word count, a lot of writers try to create longer content, naturally. This means wordiness will come into play in many cases. If your work is superior, shorter word count is negligible in terms of content that gets attention and ranks positively for the buyer.
Basically, the only "rule of thumb" I use when "editing as I go" while writing is to determine if the content is necessary to say what needs to be said. If you can say it in fewer words, do so. (Studies have also shown that the average internet user's attention span is about 5 to 8 seconds, so you have to make an impact as soon as possible or they will move on.) If content isn't captivating right off the bat, and stays that way, no one will want to read it - which means no one will want to buy it.
A tip on the side - don't write about things that you aren't truly familiar with. Too many writers try to be "experts" on subjects that are foreign to them, and it shows through in the content itself.
Just my 2 cents.