I follow them on social media etc so I can monitor their world with an occasional comment etc but don't attend their events, Birthdays etc.

You can monitor what leads do, set up listing alerts for clients for given parameters, and that's all just scratching the surface. 

Also factor in the value of sleeping well at night and avoiding the constant desire to stab your monitor with a pencil. 

I just happen to keep monitoring as I cant apply for my homestead til after my deed is recorded.

None of this is very expensive to install, but you need internet access to monitor so there is a recurring expense.

We prefer to keep it app based so that we can utilize our smart phones as opposed to going through a costly fixed video intercom monitor in each unit. 

Gates already have monitored camera so that can be more refined. 

I tell them to give me a call if for some reason they are not able to sell their house.I take them off my mail campaign list but I monitor the listing every now and then.

Is it possible to monitor that process?

To give you an example I spend about 2 hours on average a day monitoring my prospects, doing follow ups, managing my files, not to mention throughout the day I am receiving calls from responses to my marketing.