This paper aims to review literature on the impact of using web-based technology such as blogs and social networks to facilitate and promote peer feedback in ESL writing classrooms. It also investigates how giving and receiving comments from peer students can improve students' performance in writing as well as their critical thinking skills. A combination of 47 peer reviewed studies were included in this review. All these studies were found on MUN online library and the selection criteria I used in searching was studies that are relevant to: ESL writing, the importance of peer feedback and the role that web-based technology can do to facilitate peer feedback in ESL writing classrooms. The results showed that reflective assessment of peers' writing helps students develop their peers' and their own writing performance. They also stressed the role of web-based technology in providing a stimulating environment for students to reflect on peers' written work. However, some studies revealed the challenges that might affect using this technology such as students' reluctance, fear of sharing writing online and their sensitivity to being criticized publicly.