I've checked this out, and it seems to be legit.

If you participate, it sounds like you'll spend 1+ hour on your computer participating in a simulation, and get paid $75.

There was no link in the post, so I'm posting Michael's email address: mgrigoriev@macadamian.com

From emails:
I'm a user experience researcher and work with a company called Macadamian Technologies, in Ottawa, Canada. We develop software and applications for a variety of clients as you will see on the website and have been doing so for over 15 years with many major companies.

This current project is with a leading pool chemical company that is developing a kiosk in a major retailer for pool owners to perform troubleshooting on their pool using a tablet and app.

The current stage of the project requires testing the concept with actual pool owners in southern states (preferably Florida). Given our location in Canada, I'm looking at a few different options of recruiting participants, one of which is hopefully the Pool Forum.
What is a usability test?

A usability test is most often used to identify potential usability problems (in order that we may correct them) with a product. Specifically, we want to see what the user expects from the product or application, how they use the it to complete specific tasks, at what point does the user experience problems (if any) with using the product, and attempt to determine why they are having problems.

The participant is given several task scenarios, which provide a context for completing specific tasks using the product. A test facilitator observes and takes notes. Each participant will have a chance to review and provide feedback on wireframes. Together with the moderator, they will go through common user tasks, and attempt to complete these tasks.

Each session will take 60 minutes. The moderator will be asking the participant some questions throughout the session regarding their experience with the product, and finally there will be a short post-test questionnaire each participant will complete regarding their thoughts and feedback about the product.