The "Day Office" phenomena first got started in the 1980's. Fly-by-night businesses would need a temporary office to work out of. Most building managers required some measure of paperwork, which left a trail that shady entrepreneurs did not want. This forced most of them to operate out of cheap hotel rooms, which were ill-equipped for business dealings (unless it involved more "adult" activities).
A rather creative businessman in the Rogue Isles saw opportunity in the numerous abandoned offices that littered the Isles. He would turn those failed office buildings into rent-by-day operations.
The premise was simple: the renter would purchase a single office with basic office utilities such a sofa, copier, and lines for telephone, faxes, and computer networks (each of which cost extra). Furnishings would be generic. The books in the bookcases would be props. Access to the break room area would be complimentary, but access to the refrigerator would cost extra.
The business took off in the 90's with the rise of fax spam and other junk marketing gimmicks.
The business model attempted to take root in the United States, but hastily-enacted local zoning ordinances stopped most such businesses from being allowed. There were, of course, no such restrictions in the Isles, which ensured that it would be the preferred home for fly-by-night business activities.
An example of a "Day Office" was seen in "Furia and the Guardians" #6.