Hello I'm David has posted "Crowdsourcing fucks us all in the ass, and here’s how" which is a good read. He deduces those who do participate in crowdsourcing competitions are either insane, don't care about being professional, or live in India, and none of them have cotton socks!
Crowdsourcing fucks the designer in the ass because they’re rarely ever going to get paid and they can’t even plan a project properly because they’re working for the slender chance that someone will choose their logo or whatever it is from a slop bucket full of others. All they can do is think “Bish-bash-bosh, gotta bang out a logo in an hour”. And that is what you get. You get a take-away logo that is boshed out in an hour, by a student, in India, who has no socks.
The only people who benefit from crowdsourcing, are the parasites that run the crowdsourcing sites and cream heavy percentages from every project.