Few will stand to be counted as unabashed fans of the formal annual performance review. Companies including Adobe are ditching annual reviews in favor of continuous feedback. GE, often credited with championing the rigid annual review as a way to cull its herd, has been backtracking from reviews for years.

Continuous feedback isn't just a pushback against the obvious shortcomings of annual reviews, like the fact that they are infrequent and unpopular. It's a product of social and mobile tech which makes it easier than ever to give in-the-moment responses and share insights with any co-worker at any time; millennials in particular want and expect that level of feedback. It's also a natural reaction to career impatience, which has seen some workers looking for promotions before they've fully digested the employee handbook.

But as continuous feedback gains steam, it's also becoming clear that not all feedback is actually useful or constructive. Here's what you need to know to make continuous feedback a viable practice.

1. Continuous feedback won't work if people are anxious.

When starting the marketing agency Phelps, chairman Joe Phelps introduced continuous feedback not only for job performance but for individual project work. Everything in draft stage is done out in the open, to keep weak concepts from sapping too much energy on details that will never see the light of day. It wrings bad ideas out of the creative process, but it can't work if people are worried that one critical remark will invalidate their work.

"The key is to drive fear out of the company," Phelps says. "No one is able to kill your work with a single comment unless the team decides."

In other words, cultural changes that make it clear that continuous feedback is about growth, not a Twitter-like stream of roasts and takedowns, need to accompany any shift in review or feedback. If your goal is to use feedback to improve performance rather than merely reprimand, putting people on the defensive will not be an effective tactic.

2. Intent and quality could matter more than frequency.

Particularly if your company moves to a model where all colleagues are allowed and encouraged to give feedback, include training on how to give feedback that matters.

"Giving good feedback is actually one of the hardest things to do," says Jim Gallo, executive conference member of professional society HR Florida State Council. "Telling somebody they 'did a great job' or that 'they were rude' is not good feedback, that's your interpretation. What did they actually do?"

The easiest first step is to focus on facts, not feelings or impressions.

3. Continuous feedback is a nimble response to perpetual candidacy.

The job market is constantly sending signals to your employees, even the ones who appear engaged and dialed-in.

Other employers are focused on recruiting so-called passive candidates (candidates who are currently employed and not actively searching for jobs). When they're successful, they often prey upon exactly the sort of factors that can be addressed by continuous feedback: employees not knowing where they stand within the organization, or not feeling like they have a clear path to career growth. 

Moving to a continuous feedback model helps demonstrate that their efforts, abilities, and proficiencies are appreciated just as much on the job as they are on the open market.

4. Continuous feedback makes annual reviews more useful.

The biggest surprise about continuous feedback is that it can actually give more value and purpose to the annual review.

"Continuous feedback doesn't allow much time for depth," says R. David Lebel, assistant professor at the Joseph M. Katz Graduate School of Business at University of Pittsburgh. "It's not enough time to develop a really thorough action plan or career development plan."

Lebel favors a blended approach, using short questions and short sessions of continuous feedback to make adjustments in-the-moment, while focusing on the big-picture issues in the annual review.

"Annual reviews still do a good job substantiating why you're giving out raises and promotions," he says.