Telephone mast revenue on a long term lease. Sold up front for buttons. Like selling your £200k house for £60k to pay off your £20k mortgage that you were paying off in 2 years anyway.
Have you negotiated many phone mast deals?
Not many but yes. Normally 20-30 year deals with first refusal on renewal. Many sign up for extensions long before renewal is due. You do not deal with the mobile phone companies direct usually through an indirect company acting on behalf of the mobile operators. Quarterly, 6 monthly or yearly payments paid in advance. Either 1st, 2nd or 3rd year payment increases by RPI + 1, 2 or 3% above depending on contract terms.
Free money if you happen to have the land that is suitable. Personally dealt with this and know a few folk, in the local area, who have such masts.