The beauty of made up product names (invented names) is that you don’t have to worry too much about some other company having a trademark in the same space. Obviously, it’s still possibility, but the risk is far less. Imagine launching a web application and getting a ton of exposure only to discover that your product name is trademarked.
Add to that the idea that a trademark typically takes 6 to 8 months to secure, and we have a problem! Do most companies secure a trademark before launching their new web application? Or do you just hope that the likelihood of confusion is minimal?
Then look at what is happening with Hey Amigo. Based on a post they did on their blog, I gather they’re going to have to change the name. Bummer.
At the same time I’m seeing some value in having a product development blog that is separate from your product site. Because if the folks building Hey Amigo can’t use heyamigo.net then they can always fall back on their blog about it to drive initial traffic.