TrustRadius is a lead-generation and vendor-matchmaking business
TrustRadius gets paid for lead generation. When you register, you'll get matched with vendors who choose to participate in the program, according to TrustRadius. Company execs didn't say whether you're matched based on the fit with your expressed interest and desired deployment approach (departmental vs. enterprisewide, cloud vs. on-premises, etc.) or how much vendors are willing to pay for a BI-shopper lead.
In my book, vendor involvement tends to compromise things. The BARC BI study, which costs thousands of dollars, is based on thousands of customer reviews, but this publisher also has relationships with vendors whereby they can boost customer participation.
Cindi Howson's BI Scorecard is one example of an vendor-independent review source, but you have to pay for the her expert reviews and her experience. It's a small sum to pay when you consider the cost of making a bad software choice.