odesk is just your regular run of the mill outsourcing location. There's a number of them out there. I've worked with some people on odesk before, but I've found more often than not that the quality of the work is not up to par. If you have VERY specific instructions, it can be a great place to get work done, but there's definitely no free thinkers that I've run into over the years on there.
As for getting work - the problem with odesk is that you're competing directly with the lowest dollar amount. This is always a bad way of competing.
Also, just so you know, when I look for someone on oDesk I search with the following criteria - minimum 100 hours worked, active within the past 6 months, minimum 4 star reviews. I also filter out anyone who "self assesses" their work or English skills. You must pass the tests provided by odesk, and you must be in the top 85% - anything less and I won't even consider someone.
Finally, the last filter I use is the ability to follow instructions. I do not want cover letters, I do not want the sales pitch. Often I'll put in the posting "you must use the word elephant in the first sentence" - anyone who fails to do that, I don't even read the rest of the posting - I just delete them.
Crowd-sourcing can be a great way to keep costs down - but as always, since they're one off jobs, often the quality is just not there.