They did respond to me, but unfortunately, it was just template messages that didn’t provide any real specifics.

Collaborator helps us promote clients and exposure their rankings and traffic. It's a very convenient marketplace with low fees and helpful support. Google Analytics data confirms a real audience of publishers which we find helpful. Using Collaborator saves our team a lot of time and helps us promote our clients online efficiently. Thanks to a master account, we can take over all our projects in one place, split budgets, and allow customers to top up their accounts directly. If the publisher makes a mistake, Collaborator's support always helps to fix it. Whenever we place an ad, we can be sure that it will be published precisely, in the format we need, quickly, and won't disappear.

Instead of wasting lots of time in an attempt to post at least one guest article on a reliable domain a month, I can do it with a few clicks of my mouse. Isn’t it great?