In a similar way to what you do in a conference panel when you say “are there any questions from the floor?” to the people attending a public meeting (source: ldoceonline) or “open up the floor to any questions” (source) there is an on-line tool that allows you to do a similar thing in the Internet.
Here is a great explanation about what it means to open the floor for questions, from the people at Phrasemix: http://www.phrasemix.com/phrases/open-the-floor-for-questions
So, what are you waiting for? open up the digital floor to the questions now, get your free Q and A website at dilmot.com