If there are any questions the recipient can contact you with the information you provided in the signature. In addition, it is a great opportunity to promote yourself or your business by adding links to your social media profiles, websites, and business.
If you need to see and test to better understand the benefits of a HTML signature just send me a message and I will send you a sample of my work.
Please note that I am using a free hosting service for hosting the images, if you would like to host the images yourself just let me know and I can provide the images used.
As for the installation extra, I can provide instructions on how to install it and only on web based clients(roundcube, yahoo, gmail) I can install it for you (if you can setup temporary credentials for me).