Why does it matter? Do you think a company intent on providing a good value to conference attendees will accept anyone just because they offer to pay?
If I were running a conference like that: 1) I would want to be paid; 2) I would accept presenters only if I thought they could deliver value to other participants in my conference.
If attending conferences like this is equivalent to paying for advertising then so what? It can be worthwhile to the company presenting (as long as they are presenting with other companies of good quality).
I have invested in at least one company encountered in such a conference.
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