We started to use Webex because it's user-friendly, reliable and secure. The main advantages are:
to take part in a meeting you don't need an account,
no extra software is needed to use Webex
it works on all desktop computers, tablets and smartphones
to invite participants for a meeting you only need a name and an emailadres
even with a group of 10-15 participants the AV-quality is fine and interacting is going well.