This website exposes the flat earth deception and proves that the earth is globe shaped.
Here’s a video from Paul On The Plane, showing the billboard that flat earthers paid for, to promote their FE2018 conference in Denver, Colorado.
The flat earthers who were attending the conference had a meet up at the sign, which is just off of highway I-70, so no doubt many drivers noticed them and the sign.
The interesting part is that they didn’t offer ‘seekers’ a way to attend the conference for free. So someone who saw the sign would learn that they have to pay $40 for online access and $249 to attend the conference; and I doubt maybe people would do that.