Ongoing Customer Care and Contact Reminders

Ongoing Customer Care and Contact Reminders

Hey,
We rent heavy equipment and most of our customers rent repeatedly. I can see how Zoho is really useful for sales funnels that "close" like buying a car but I am struggling to get it to help us.

Our sales process is like this:
-We make repeated contact with a potential client
-They rent from us
-We stay in contact with them (to remind them that we're here if they need us)
-They rent again
and it just keeps going.

Basically, there isn't an end to our funnel. As soon as they buy, we are selling to them again.

What are some ways that you've seen to use Zoho to manage ongoing customer care and contact?