Ilya Semin is the founder and CEO of Datanyze, the sales prospecting solution that tells you who's trying your competitors' software.

Every entrepreneur or sales development representative has been there: Staring glassy-eyed at a list of prospects that continue to elude you despite significant time investment. One prospect promised to email back but never did while another contact left their company. Or maybe your schedule has been so full that you forgot to follow up with that promising lead, who now sincerely doubts your commitment to the sale.

No matter the reason, your list of leads appears dead with no hope of revival. But before you bury your list in the cold-case files, consider these tips--gleaned from my time building software for sales prospecting--for reviving even the coldest of leads:

Keep It Simple

One of the biggest challenges anyone in a sales role faces is communicating the value proposition of their products or services in a way that is both powerful and succinct. In the digital age where ideas are expressed in 140 characters or less and the average consumer's attention span is a mere eight seconds, getting bogged down in features, details and cheesy acronyms is a surefire way to get hung up on mid-sentence. If your prospect didn't buy into your initial pitch, odds are good that they won't want to hear the details.

It pays to do some prep work before re-engaging. Whittle down your script to focus on a specific problem you believe the prospect is facing. Then, tailor the pitch to highlight your product or service as a solution to that problem. If something about your offering has changed, or you have a new, relevant use case since you last connected with your prospect, bring it up. But be sure to keep it short and sweet.

Don't Ask for Money Yet

Nothing turns a prospect off faster than boring details--with the possible exception of asking for money. If economics really are a key differentiator, you should feel free to highlight that fact. But, asking for feedback is a much more productive use of your time than asking for money, at least initially. There's a time and place for everything.

Think Ahead

Don't simply offer a one-and-done solution. Think ahead to your prospect's future needs and highlight them in your discussion. Show that you've done your homework by reading up on the company's recent news coverage, by following their social media channels, by participating in webinars and by reading company reports. Have there been any major shake-ups that will affect their industry as a whole? What key challenges or opportunities do they face in the next 12 months? How will your product or service help address these issues?

Mix It Up

Experiment with different follow-up cadences for phone calls, and try sending emails at different times to see which get the best response rates. For example, try emailing C-level prospects on Sunday evenings when they are likely to be online prepping for Monday morning, and connect with people on LinkedIn during the platform's peak hours. Additionally, A/B test various subject lines to see which messages resonate and adjust your email strategy accordingly.

Clean Up Your Dirty Data

Many cold leads have been sitting in a CRM system for months or years, collecting dust except for the occasional newsletter blast or tradeshow invitation. When trying to revive a cold lead, nothing could be worse than contacting the wrong person and fumbling on the phone as you try to pretend you're up-to-date on organizational changes. As a best practice, data should be cleaned, validated and organized every 30 to 60 days. But, there are tools to help automate much of this laborious process and even ensure your list is constantly updated in real-time.

Get Social Media Savvy

Never underestimate the power of social media when it comes to cultivating relationships with potential clients. On LinkedIn, leave a brief note before sending an email or making a call. Are you following prospects on Twitter? Engage with them by re-tweeting their handles, "favorite-ing" their updates, sharing useful articles and even commenting on similar interests like sports or music when appropriate. Learn how to serve as a resource without becoming creepy.

Keep a Close Eye on Competitors

So you lost a cold lead to a competitor--it happens. Don't let it get you down. Remember that nothing is permanent and that your former prospect may be experiencing issues with their new service or approaching the end of a contract. Your stolen lead might even decide to cancel a subscription after a one-month trial.

There are tools available to track which web technologies prospects are using--or dropping--on any given day, providing intelligence to help re-engage leads in a timely manner.

It's your responsibility to bring cold leads back to life, but at the end of the day, it's also important to remember the 80/20 rule: "Focus on 20 percent of the actions that will deliver 80 percent of the results." This translates tofocusing on those 20 percent of prospects that will turn into 80 percent of sales. Last year, how often did you keep working on an unresponsive lead? How frequently did you bounce emails around with someone whose budget for your product was still unclear? How much time did you waste searching for email addresses that turned out to be useless? How often did you reach out to prospects who weren't even in your market?

It's time to get down to real business. Be honest with yourself about which now-cold prospects are worth pursing, and which ones aren't. And when it comes to determining which are which, it's often the quality of your data that will make the difference.