Contact
There is no form — the site is static, and a form would collect personal data nobody needs. An email is enough. This page is sorted by what you want, and each link prefills the subject line so the mail is already sorted when it arrives.
A figure is wrong
The most useful message we can get. Corrections are checked and dated — including those from vendors, with nothing given in return. Helpful: a link to where the figure appears, and the source that establishes the correct one.
Being added to the comparison
Vendors who are missing are welcome to get in touch. A place in the table cannot be bought and inclusion is not a recommendation — the same research applies as to everyone else. Useful: the product page, a price or the statement that none is published, and the category the product belongs in.