Whether you do it via that site or this one, the basic method is the same. Register anonymously with an alias on one of the sites, then write a comment on any page or post stating your willingness to help. Someone will contact you using the email address on record for that user name.
The dot-org site is for people willing to create or administer a non-profit organization to Make Society Work. This dot-com site is intended for the use of volunteers, but there is no reason why commercial activities may not be involved. Linux is Open Source software, for example, but there are commercial organizations like Red Hat which make a profit from it.
I prefer to consider only the activities of volunteers, but human society is all-encompassing, and cannot be so restricted.
I see Making Society Work as more of a movement than a project, and like all large movements it will address the problem in many ways. Some will be through non-governmental organizations, so with the help of governments, and some will involve businesses. See Commercial Applications of Social Technology for more information.
Personally I have no interest in business or commerce and will not accept any money for my own activities, not even any recompense for the large sums I have spent on websites and other things.