Alert Labs interview questions

3 interviews: 1 with the HR director 1 with the VP of sales 1 in person interview with their marketing director and a short conversation with their top sales person at their Kitchener offices. The process was quick and easy, but even though there were 3 interviews there was not even one polite email to say that I was not moving forward in the hiring process. I know companies have lots of applicants, but after 3 interviews, after commuting to their head quarters (3 hours driving in total) and after sending thank you emails with follow ups the least that a company can do is to notify the candidate that they have decided to pursue other candidates.