How do we know Elance & others are not a scam?

Yes, I know overall these sites are not scam sites.

But how do we know that internally they are not posting fake jobs so as to use more of our credits so that we have to buy more?

I get this feeling because I really think/want my reply rate for jobs to be higher... especially when I look at others who have bid on the same job (sloppy looking profiles from overseas).

This was all just a thought and not trying to start a discussion about effective ways to improve efficiency on these sites.

But the user would never know if this was happening and there is much incentive for these sites to do it!!!

I get the same feeling after i read your post!!

You have to look at feedback I'm sure like everywhere else there are probably tons of scams on there as well.

Well the credits shouldn't be that big of a cost to acquire new business. If you are concerned about the cost of credits, your return on investment isn't big enough and you need to rethink your strategy. Don't just indiscriminately bid on jobs. Look at the persons previous dealings history, look at how many jobs they have awarded in the past. Look to see what other people are bidding on them. On elance I have too many credits, I dont even use them all because I only bid on jobs that I think will have a good chance of actually hiring me.

Check out their profiles. See if they have all their full profile info filled in and they look like a legitimate company before bidding.

Also, I wouldn't be so concerned about insiders posting fake job offers, I would be more concerned about your competitors doing it. Many competitors will post TONS of enticing looking jobs to distract you and use your credits, and then they can focus on the real jobs.