Networking, and particularly online social networking, gives you access to very large marketplaces and allows you to interact with younger people who have grown up with the technology.
Fortunately, for those of us with grey hair, and a preference for fewer emails and more privacy, the internet offers many alternative networking sites.
In order of (our) preference, these are -
We have found both Slideshare and Yudu to be very useful for the presentation of PowerPoint shows and online brochures successively.