When negotiating your cell site tower or rooftop lease there are many things that you need to know. Obviously the lease rate is important, however there are other provisions that can affect your overall 'life of the lease' totals as much or more.
Co-location rents or fees are very important as they allow you to collect a portion of any sub-letting the tenant, the cell phone or data carrier, collects from additional carriers the tenant adds to the cell site.
Escalation of your rent each year or 5 years can also make a big difference in the 'life of the lease' total amount collected. Normal escalations are 3% yearly and 15% each 5 years. The 3% yearly escalation will actually give you a little more due to the compounding.
Read more at Negotiating a Lease.