All I could find was the same question on Ask HN from 2009 (https://news.ycombinator.com/item?id=494831). Have times changed? When do you trademark: when starting out or once you start having customers?
Filing a trademark is easier than finding customers.<p>Therefore it is a distraction.<p>It is pretend work to avoid hard work that is most likely fruitless.<p>Once the business is successful enough when "We need trademark" is all you need to say for a team of lawyers to make it happen, then it might make sense.<p>Good luck.