SquadHelp.com is a crowdsourcing contest-driven site similar in concept to SloganSlingers.com and GetASlogan.com. Businesses come to SquadHelp looking for a lot of different things, from slogans and taglines to company names and logos. You can sign up as a contributor for free, and you can enter any contest that isn't restricted.
The contributor chosen as the winner by the contest holder for a specific contest will win the set prize amount ($50 or more) minus a 10% fee taken by SquadHelp. When you win a contest, the prize amount is deposited into your SquadHelp account, and you have to request a payout (via PayPal) to receive your money. You can request a payout any time you have $20 or more in your account. In addition to receiving money when you win a contest, you can also earn site points and badges.
SquadHelp is a good site for slogan writers to sign up with, because it's free and there are a lot of opportunities to make money. You can only submit a certain number of entries to each contest, and depending on the contest holder those entries may or may not be rated. The site design is a little busy-looking, and it takes a while to get used to the layout and where to find everything, but generally it's easy to use.
Thanks to Wylie for suggesting this website.