CareerBuilder recently conducted a survey in which they asked 5,518 job seekers and 2,775 hiring managers about deal breakers when trying to land a new job or find the right candidate; what job candidates expect from prospective employers; and what employers expect from job candidates—among other things.

The survey unearthed some unique (and surprising) insights and lessons for job candidates and employers alike.

“Traditional notions of what employers and candidates expect from one another are not necessarily applicable today,” says Rosemary Haefner, vice president of human resources at CareerBuilder. “Expectations and behaviors have evolved with new technologies, greater access to information and workplace environments that have become more flexible. These lessons are designed to help job seekers and employers to connect with one another more effectively.”

Here are nine lessons from CareerBuilder for job seekers and recruiters that might surprise you:

As an applicant, be prepared to speak with the top brass. Prepare for every job interview as if you’ll be speaking with the CEO or other senior leaders because that may very well be the reality for some candidates. According to CareerBuilder, 38% of employers say that job candidates are required to interview with a C-level executive (CEO, CFO, COO, etc.) within their organization.

Make sure your online persona is free of “digital dirt.” This one might seem a bit more obvious—but too many job seekers don’t take it seriously. This might surprise you, though: According to the CareerBuilder survey, 62% of employers use the Internet to discover additional information about a job candidate. About half (48%) use Google or other search engines to research candidates; 44% research the candidate on Facebook; 27% monitor the candidate’s activity on Twitter; and 23% review the candidate’s posts or comments on, or other rating sites.

Another tip: Don’t wait until you land an interview before you start cleaning up your online presence. CareerBuilder found that some of the search activity happens before candidates are even called for a job interview.

Proper etiquette is required (throughout the entire process!). While it’s imperative that job candidates make a good impression during the interview, they also need to reinforce it afterwards. The survey found that 58% of employers said it’s important to send a thank you note after an interview; 24% said it’s very important.

“While seemingly standard, this is a practice that’s often overlooked and could ultimately hurt your chances of getting hired,” Haefner explains. “In an earlier study we found that 15% of hiring managers said they would not hire someone who failed to send a thank you letter; 32% said they would still consider the candidate, but would think less of him or her. A thank you note enables you to reiterate your enthusiasm for the opportunity and why you’re the best fit for the job. You don’t want to skip that step.”

Practicing good etiquette shouldn’t stop there. If you don’t get the job, never bad mouth the employer online or to your friends. You don’t want to burn any bridges.

If you’re not mobile as a recruiter, you’re not truly accessible. Nearly two in five employers (39%) have jobs that stay open four months or longer due to the inability to find people with appropriate skills. Since mobile job search is growing at an accelerated rate, employers who aren’t mobile-optimized are missing out on key talent they need to find quickly, CareerBuilder says.

As it turns out, at least half of all job seekers with smartphones or tablets spend three hours or more looking for jobs on those devices every week. About 65% of workers who search for jobs via mobile devices will leave a website if it is not mobile-optimized; and 40% walk away with a more negative opinion of the company.