I do some work on Elance as a writer. The only item in my "portfolio" on Elance is a short 500 word piece on why looking at portfolios is worthless. A few reasons:

1)There is some portfolio fraud. Every once in awhile a job listing pops up from somebody who says they are looking to be a freelance writer and need samples for their portfolio. It probably happens even more often but I usually filter out listings from India, etc.

2)At least on the writing side, most Elance clients forbid you to use the work you do for them in your portfolio. This means the work you see is usually work they polished specifically for the portfolio and is not indicative of their normal work.

5 star ratings are a dime a dozen on Elance. At least on the writing side the convention is that anything less than 5 is a serious knock on them. If a person is merely competent then you usually don't leave feedback at all.

And please don't take the advice of the person saying to ask the proposal writer to put a keyword in the proposal. A lot of good people take that as an insult. Do what you do and only look at proposals that address the requirements. That is what my portfolio piece says people should do instead. Look at the strength of the proposal and not the portfolio.

By the way, if you are ever looking for a writer for any of your websites feel free to contact me at the email in my profile.