кто пользовался ими, полезные?

Test your target audience – When choosing users, you can specify the following demographics:

Gender
Age
Country
Income
Web Expertise
Other — This is where you can specify additional requirements such as “small business owner” or “Facebook user with 200+ friends”

Facts about our users:

Are not our employees. About 85% reside in the US, and most of the remaining 15% are from Canada and the UK.
Normally participate in studies very infrequently because we have more users in our database than we have work opportunities. This is important so they remain like a typical Internet user.
Have a wide variety of web experience, from beginning user to expert.
Have been rated highly by customers in previous usability tests.
Receive $10 per usability test. (Apply to be a user tester.)

Our Guarantee: The users who test your website will deliver a video and a review with very helpful observations. If that doesn’t happen, then get a refund.