This study aimed to find out the impact of "text mining and imitating" strategies on lexical richness, lexical diversity and general success of students in their compositions in second language writing. The participants were 98 students studying their first year in Karadeniz Technical University in English Language and Literature department. Participants in the experimental group were instructed on how to use mining and imitating strategies in their essays to be more competent in vocabulary choice while writing. On the other hand, students in the control group were only instructed on how to write their essays following lesson plans. After treatment, participants in the both group were asked to write two essays. A corpus of 15826 (control group) and a corpus of 25027 (experimental group) words were compiled in two months, and these essays were tagged using a computerized tagging system (Biber 1993). Though there is statistically slight difference in terms of lexical richness, the study revealed that compositions in the experimental group are lexically richer than those in the control group. Common nouns and general verbs subclasses were found to be used more in compositions of the experimental group. In addition to that, students in the experimental group received significantly higher grades than those in the control group.