Common words don't do well as names when they are words that describe exactly what the company does. Common words can be better used when they have nothing to do with what the company does.
For example, Apple is a much better name for a computer company than "Computer", would be. Same Amazon is much better for an online bookstore, than "Bookstore.com" would be.
The reason they are better is because they can be uniquely associated with that company. How many Apple companies are there that sell computers? How many Amazon's that sell books?
They use a common word to actually turn it into an unique one.
Sex.com like names are usually highly valued as domains because of the perception people have on them, thinking that a name so descriptive MUST be valueable as a brand.
It's actually absolutely worthless as a brand name, and if you follow the track records of the companies that have used domain names like that you'll see that most of them have failed. Sure it might help a little bit with SEO, but that benefit is not nearly enough to compensate for how bad a brand like that is and how easily people will forget it.
As for what Marc said, I agree with the fact that their approach was not about the automation is probably the biggest factor in their eventual failure. However, the Wesabe name did create some friction as opposed to Mint.
When you have a bad name is like trying to drive a car with your foot slightly pressing on the break pedal. No matter how fast your car (product) is, your speed will still be dramatically reduced.
I was being facetious, but I do partly agree with you. A bad name does hurt. Wesabe isn't a good name; it comes off as syllable salad. Mint is a much better name.
On the other hand, plenty of successful companies have terrible names. 'Google' is just as bad as 'Wesabe' - and Google's early adopters had to find them without access to a good search engine! I'm sure that Wesabe could have succeeded in spite of their name if their product had been competitive.
