Exchanger isn't a great domaining keyword but .pro makes it sound better than any other extension.
Here is a product called Heat Exchanger Pro;
http://www.mytub.co.uk/product_information.php?product=354208?ref=BASE
This is a $550 item with the word Exchanger in that somebody has chosen to add Pro to as a branding suffix.
The marketing person who made this decision didn't have 5-6 gTLD's to pick from, they had 250,000 distinct English words.
.pro is a zen like domain extension precisely because just about every keyword fits it. If your website is called Widget.pro, you are telling people that your widget is better than the standard widget, that you know more about widgets than other widget sites, or that you will help users find the lowest widget price or the best widget.
With other extensions you are not communicating any extra information with the keyword, the use of the extra letters is a waste. People like to consider themselves a pro. If you put the phrase "I'm a Pro" into Google with quote marks you get 816,000 indexed occurences.
There are 1.62m indexed Google pages that end Pro.com. That's hundreds of thousands of keywords where somebody has said Keyword.com is registered, what's the best word I can add to my keyword and still get a short impressive .com that communicates what I want to say to users?
Please can you tell a valuable domaining keyword (ie where the .com has or would sell for alot of money) that doesn't go with .pro?