We already know that the world is built on connections. After all, it is about who you know and not what you know, right? With that being said, the busier you get, the less time you have to spend on unproductive meetings because, well, you’re busy working on revenue-generating activities.

The problem is that you already encounter these terrible engagements on a regular basis and if you’re not paying attention, you’ll find yourself trapped in a seemingly never-ending cycle of worthless meetings. This quickly leads to what I call “personal-time decay,” where your ability to be as productive as required at the office is inhibited by worthless meetings, forcing your productive time to cut into your personal time -- which is kind of like tooth decay.

The good news is that there is a fix for such for such a menacing problem: be a lot more selective about the meetings you take. To be clear, I’m talking purely about meetings that are meant to be productive and based solely around advancing your business goals, not social meetings.

Related: The Entrepreneur's Two-Letter Money Maker: No

So, how do you identify these time wasters in advance? Let’s take a look at a few.

1. A loose connection from a friend or colleague.

These are probably the most prevalent of potential meetings and, therefore, you must pay particular attention to them. The story goes like this: You’re at a friendly gathering, chatting with a few friends about business and enjoying a nice cold one when someone says to you, “Hey, I have a good friend that you should really meet. I think you guys would hit it off.” Your natural response should be, “great, thanks,” but in reality you should never take such a meeting, as the likelihood of it resulting in anything productive is almost zero.

If and when your friend actually takes the initiative to email introduce you and the friend, set up a 10-minute phone call as an introduction -- because you are “running low on bandwidth right now” -- to determine whether taking an hour or two out of your life to get together in person makes sense.

2. Looking for "advice."

This is another perfect example of a meeting that makes almost no sense to have, at least in person. Let me be clear: I’m all about helping other people and providing guidance on issues where I may have expertise. I believe mentorship is critical to early success and is largely why I take so much joy in writing these “how-to”-based columns. With that said, as you get busier and have greater success -- whatever that means to you -- the time to help everyone that asks for it just simply won’t be there without causing personal-time decay, which you absolutely must avoid.

Instead, when warranted, set up a 10-minute call while remembering that, as much as you’d like to, you can’t help everyone that asks for it.

Related: How Much Should You Give Away for Free During a Coffee Meeting?

3. When someone cancels a meeting close to its scheduled time.

You’ve had the meeting or call scheduled for weeks, and seven minutes before the meeting, you receive an email: “sorry but something has come up and we need to reschedule.” This is one of my biggest pet peeves because it means that they couldn’t care less about the value of your time, which was blocked off for 30 minutes and is now empty, and there are clearly more important things going on than you. This goes against pretty much every sales and emotional-intelligence rule in existence.

That person has now set a precedent -- if he or she is willing to cancel or move a meeting that close to the scheduled time, for whatever reason, the likelihood of it happening regularly is high -- and you don’t have time for that. Instead, just say, “Thanks, but we’re not going to be a good fit to work together” and move on.

4. A blind intro.

These are the worst -- you get a random email out of the blue from a friend who is introducing you to someone else for an unknown reason. But there’s always a reason, you just don’t know it because your friend is inconsiderate, as indicated by the blind intro. He or she should have, instead, asked you if you’d be interested in connecting with this person prior to sending the intro, allowing you to gracefully back out if necessary.

The blind intro is rarely, if ever, going to result in being productive, if even just by default of the way the intro was conceived. This case, like the others previously mentioned, should at most give way to a 10-minute phone call -- and a serious dead arm for your friend.

Related: Don't Be a Networking Frog