Professional development (PD) is a vital part of teachers' ongoing growth (Fischer et al., 2018; Wei, Darling-Hammond, Andree, Richardson, & Orphanos, 2009). Evolving technologies allow for new and different forms of PD, and online PD is proliferating (Bates, Phalen, & Moran, 2016; Fishman et al., 2013). Scholars have argued that online PD has unique and substantial potential to reach teachers across the globe (Dede, Ketelhut, Whitehouse, Breit, & McCloskey, 2009; Robinson, 2008), and international policy advocates the use of PD as a mechanism for teachers’ continued professional learning (eg, Jensen, Sonnemann, Roberts-Hull, & Hunter, 2016; UK Office for Standards in Education, 2006; US Department of Education, 2010). Teachers have begun to create opportunities for their own informal professional learning through social media, such as Twitter (Carpenter & Krutka, 2015; Colwell & Hutchison, 2018; Macia & Garcia, 2016).