This document describes a system to predict customer purchase intention from social media posts like tweets. The system was developed using a dataset of 3,200 manually annotated tweets relating to the iPhone X. Various machine learning models were tested on their ability to classify tweets as indicating purchase intention or not. The models were evaluated based on accuracy, precision, recall, and F-measure. The best performing models were logistic regression with a binary document vector, achieving an accuracy of 80.8%, and SVM with a TF document vector, achieving 80.5% accuracy. The system aims to help companies better target advertising to potential customers based on analysis of their social media data.