Hiring top salespeople is key to having the best sales team that consistently hits its sales targets and successfully brings in revenue. Unfortunately, though, hiring salespeople is a challenging task. Turnover in sales is exceptionally high because most sales professionals are actually duds. Only 40% of sales professionals in North America will hit their sales targets and only 10% will deliver ROI. The rest will disappoint.

In order to avoid hiring a bad salesperson, you need to know how to spot those who will fail you during the interview process. Use these tips to weed out the bad apples.

Be Wary of Charm

There are two types of salespeople: the good ones will know how to sell products and the bad ones will only know how to sell themselves. You’ve probably made your fair share of sales hiring mistakes in the past, and some might have occurred because you got caught up in the charm and charisma of a bad salesperson. The candidate may have won you over with a shallow smile and fake promises. Just because a salesperson can sell himself doesn’t mean he’ll be able to show results when it’s time to sell your products. Don’t fall for charm during the interview.

Ask for Numbers

If you want to avoid hiring a bad salesperson make sure to ask about numbers during the interview—numbers are one of the most effective telltale signs of a salesperson’s capabilities. Understanding past performance can indicate future performance at your company. Ask for past sales reports and sales metrics and KPIs. A successful salesperson will want to track his personal progress and will be able to give you the answers you seek.

Don’t Fall for the Know-It-All

We’ve all come across the know-it-all sales rep. The sales professional who claims to be the best at what he does, who thinks he can sell anything, and who thinks he doesn’t need to be trained. Though you might be tempted to hire this person because of his confidence, you might just end up hiring a bad salesperson. The know-it-all professional will likely be un-coachable, rub the rest of your team the wrong way, and constantly create friction, while being unable to deliver results. These sales reps are too good to be true, so don’t fall for the act.

Take Unpreparedness as a Red Flag

You might want to forgive a candidate for being unprepared for the interview, but this is actually a huge red flag that can indicate a bad salesperson. Sales is competitive and requires great organization. Sales people need to be prepared and learn everything they need to know about their clients’ businesses, competitors, and needs. If your candidate can’t be prepared for the interview, he likely won’t be prepared for sales calls either. Interviewees should know about your company’s past, your products and services, your industry, and your competitors during the interview.

Be Careful of Nomads

You might be impressed with a candidate’s past experience because he seems to have worked just about everywhere. This should be seen as a red flag, not an advantage. A candidate with an unstable job history should be approached with caution. Through there are some reasonable factors that contribute to short tenures at past employers, if a candidate can’t explain why his previous jobs didn’t last and why working at your organization would be different, move on. He’s likely a problem employee.

Pay Attention to Social Awareness

Sales is a highly social industry. Your sales people need to be able to read their clients, read the social situation, and base their words and actions on what they perceive from the situation. A candidate that lacks manners, is socially awkward, says inappropriate things, or doesn’t stop talking might be a bad salesperson that clients won’t be able to relate to.