In many coop offering plans there is a special class of shareholders called Holders of Unsold Shares who have rights and privileges not enjoyed by the ordinary tenant-shareholder. The more unsold shares there are in a co-op, the less clout the other tenant-shareholders have. If the coop has a majority of unsold shares it is difficult to obtain financing since the coop is less than 50% owner occupied.
Holders of Unsold Shares are not required to submit their prospective purchasers to the board for its approval, nor are they bound by the board's sublet restrictions. Holders of Unsold Shares are allowed to sublet their units at market rates in perpetuity. They're also exempt from paying sublet fees, alteration fees, transfer fees and flip taxes which may be imposed on the typical tenant-shareholder.