It was never really a mail order catalog in the sense that there was no single place to order the stuff (the Whole Earth store did open later, but it just a slice of what appeared in the WEC and CoEvolution Quarterly). It was, as others have noted, reviews of "good stuff" and info on how (maybe) to get it.
That came later, when they opened the store. It only applied to stuff they decided to carry, though given that they reviewed it in print that was likely because the reviews were almost all positive.
No problem! Lucky for us they uploaded all the issues of the catalog. : )
If you look on the Wikipedia page there were a few related physical stores over the years:
> the Whole Earth Catalog was preceded by the "Whole Earth Truck Store" which was a 1963 Dodge truck. In 1968, Brand, who was then 29, and his wife Lois embarked "on a commune road trip" with the truck, hoping to tour the country doing educational fairs. The truck was not only a store, but also an alternative lending library and a mobile microeducation service.
> In 1969, a store which was inspired by (but not financially connected with) The Whole Earth Catalog, called the Whole Earth Access opened in Berkeley, California. It closed in 1998. In 1970 a store called the "Whole Earth Provision Co.", inspired by the catalogue, opened in Austin, Texas.[27] It has six stores in Austin, Houston, Dallas, and San Antonio.
The Whole Earth was never really anti-capitalist. Rather Brand and company leveraged the ideas early cybernetics research to build loose networks of engaged individuals with the goal of creating their own centers of power and authority in society and the economy.
The Whole Earth Magazine seems much more interesting than the Catalog