Udimi is a solo ads marketplace where sellers and buyers contact each other to trade solo ads deals. The site is free to sign up and the best thing about Udimi is how fast you can get started with it. What makes this solo ads marketplace different from other solo ads websites is that Udimi guarantees the traffic. This is a great avenue to begin getting your offer in front of potential customers.
Superior Solos is a solo ad vendor who allows you to target specific niches. Unlike other solo ad marketplaces, Superior Solos broadcasts your offer for you, and they guarantee 100% real traffic. They use AWeber as their autoresponder, so if you use AWeber you are familiar with how that works, as far as how they broadcast to their subscribers list.
Easy Solo Ads is different from other solo ad vendors, in that it is a subscription service. They offer to help with ad writing, and targeted marketing. The nice part about Easy Solo Ads, is that most of the work is done for you, of course at a price. Their cheapest plan starts at $27.00/month.