I came to this conclusion on my own when I worked for TechInsurance. I was the sole web developer for TechInsurance.com and BusinessInsuranceNow.com for 6 years. As I soon found out, my job became much more than just programming. I found that a large portion of my time was spent improving the user experience of the two sites. And I'd find that time and time again, even when the instructions were staring the user in the face, they'd gloss right over it and call us for help.
You might be tempted to make things bold, or some sort of loud color which surely has its uses. But you have to be careful here, because if you go overboard you can end up with multiple elements fighting for your attention and no real improvement is made. So often the first thing you should focus on is stripping away text that isn't crucial so as to make everything as concise as possible.
"Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away." - Antoine de Saint-Exupery
I've taken this lesson and applied it to BucketSoft products. I've even put it to the test on a few occasions at ux.stackexchange.com. One of the better examples is with this question about email activation. The person asking the question had a website that required account activation after the user registers. So after the user registers, the site presents the user with this message...
Instructions on how to activate your account have beem emailed to you. Please check your email.
I felt this could be improved. First, I felt like the word "instructions" made the task sound more daunting than it really is. Second, I thought the user might be glossing over this message if there's nothing there to grab the user's attention. So I suggested changing it to this...
We've sent an email to firstname.lastname@example.org. Open it up to activate your account.
"Almost done..." is a very effective attention grabber, and with a simple wording change the task now sounds like it'll be a cinch. So after this change, the abandonment rate dropped from 25-30% to 5-10%.
And it turns out there have been other studies that illustrate the importance of being concise and to the point. Jakob Nielsen has been one of the more influential usability experts on the web over the years and he has an article from 1997 titled, "How Users Read on the Web." In his article, he came to many of the same conclusions I did. But he has some hard data to back it up. He even mentions that, "In research on how people read websites we found that 79 percent of our test users always scanned any new page they came across; only 16 percent read word-by-word."