This is one reason even small startups should consider registering their trademark. Depending on timing, it wouldn't necessarily have prevented Google or its p

This is one reason even small startups should consider registering their trademark. Depending on timing, it wouldn't necessarily have prevented Google or its predecessor in interest from registering and using the domain, but it could prevent Google from re-purposing the domain for use as they have here. Just because the prior company was using the name in commerce for a different purpose doesn't necessarily mean that they can then turn around and use it in a confusingly similar manner in a different area. While there are common law trademark rights that base on usage, a registered mark could have been a valuable tool in preventing this kind of cross-purpose usage.