Todd Spangler NY Digital EditorOver nearly eight years, YouTube stars Veronica and Vanessa Merrell have never missed a weekly video upload to their channel.That work ethic has helped the identical twins grow their fanbase to nearly 6 million followers on the platform for their comedy sketches, original songs, vlogs, and other light fare.And their tenure puts the Merrell Twins, now 24, in a class of OG digital influencers.