If you are already engaged in a wireless lease with a wireless carrier or cell tower company, then your property currently exists in more than one database. Wireless carriers already know where you are and you will likely be the first landowner approached when they are ready to expand or augment their existing networks, because you have already been through the zoning approval process.
Cell site leasing is a complicated business. The only possible way marketing could be effective is in the case where the company who wishes to market your lease represents a wide base of wireless carriers who desire to expand their networks into your particular area. In addition, only tower owners can market cell sites, so if you are not the tower owner, nothing can be done.