My supervisor from my final year project on my BSc (a search engine that predicted the likelihood of each result returned being accessible to screenreaders) offered me a PhD position. As it was ESRC funded, I had to take the topic I was given, which was User Profiling. I worked on it part time for six years and managed to get one paper published: https://www.academia.edu/9385444/The_Unified_Profile_Applying_User_Profile_Data_Within_Intelligent_Environments