I think oDesk's rating system is fundamentally flawed and is designed for short term, quick contracts, when long term contracts bring in all of the revenue. I've just had my rating drop from a flawless 5 on a long-term contract with a client I've been working with for almost 3 years. We decided to close one of my two contracts to consolidate and attempt to fix an oDesk glitch that made my earnings disappear, and he deducted 1 point on availability (overall rating of 4.85), which, given that I am working with him full time, I find both amusing and sad.
Since I have worked over 1000 hrs on that contract and received 5 digit bonuses, it's impossible to ever recover from it. My rating is now 4.9 which is really not a bad rating, and a 4.85 from my client is like a 10 out of 5 with most clients, but I know that the rating will hurt me because some clients will look at it and think I am not dependable since someone gave me a lower score on availability. I know that there are those that will disagree and find perfect 5s questionable and automatically assume that someone can only have a 5 by having refunded bad ratings. I disagree. I take a lot of pride in my work, always over deliver and go the extra mile, and provide additional value on a consistent basis, so I do feel I earn them.
I know I could always ask my client to change the rating, but that just seems wrong. oDesk should ensure that a single rating on a long term contract can't tarnish the overall rating for life. There are many ways to do this. The simplest solution probably is to auto rate every quarter, six years or even once a year (or every $25k/$50k). This way a subpar rating would only affect a fraction of the total contract size and ensure that the contractor could one day recover from it. Since long-term contracts over years not only bring in the bulk of the revenue but are the lowest maintenance contracts for this platform, oDesk should focus on encouraging them, not sabotage them.
Yes, as you say, the nightmare scenario is to have a long-term client giving you a poor rating that can signifcantly damage your chances of securing lucrative work. I personally feel the ratings are too complex anyway, why not a thumbs up (With comments) or a thumbs down (With comments)? This would end the paradox of clients damaging careers despite actually liking the work they recieved.
I say the rating should rather be adjusted/normalized so that they actually give useful information. When everyone is inclined to give everyone else 5 stars, I just don't see it as a useful system. Same reason I don't rate my music library; it's self-selected to be things I already think are 4 and 5 star songs. Relative, aggregating systems like Netflix uses are far more helpful.
Not knowing the algorithm oDesk uses makes it hard to suggest any changes, though. The bottom line is that nobody should have 5 stars, even if all their ratings were 5 stars. There will always be some stat that somebody is lacking that, especially for a particular match, will impact the suitability of a candidate. I don't care how great a client is to the people they hire, they are not a 5 star client to me if they're paying freelancers an average of $5/hour, and likewise I should not be a 5 star freelancer to them if they're looking for that kind of cheap labor.
You still have your five star average. I've watched your profile with supportive benign interest since you started over a year ago (fellow countryman, same specialty). I was one of the first people to encourage you and advise you to raise your price. Over a year later you've got a realistic price (but still room to raise it) - and 60+jobs under your belt. Then guess what - someone marks you down on one sub-star and you come on and whinge about it. The reason your average hasn't budged despite that imperfect score is because it's such a small job. The reason you've had a perfect card so far is that you've openly on here discussed refunding people for less-than-perfect scores.
So, I was first gobsmacked that you should come on and complain that someone has ruined your perfect average - well guess what, everyone has a perfect five stars until the day they don't, and that day has come for you. So do you whinge about it or get over it?
Well, that was as far as my feelings went on the matter, until I saw your profile today for the first time in a few weeks (it's not visible through the forum). And for the poor client who marked you down one little substar, instead of taking it on the chin, you have publicly complained on your own profile about the score you were given, and the "vagaries" of clients who don't give perfect fives. Not on this forum mind, but on your own profile, right at the top.
So now a client looks at your, at first, promising profile, and may as well read "don't bother coming near me unless you're going to give me perfect scores - how do you think I kept it so good so far?"
So in the next few months, if you get less offers, blame it on the robots, by all means - but it might just be you have to look a bit nearer to home. Let's just say that if there was a star band for professional conduct, you would have lost your perfect five a lot sooner.