The 5 Biggest Mistakes Marketers Make Using LinkedIn's InMail Investing a little time for refining your InMail B2B email marketing campaign is likely to produce a worthwhile return.

Currently, LinkedIn boasts more than 467 million members in over 200 countries. When used correctly, LinkedIn's InMail is an incredibly powerful tool for laser-targeted B2B marketing.

While using InMail to get your message in front of a receptive audience sounds great, unless you know what you're doing, you can easily waste your marketing budget on campaigns that don't convert.

Here are some of the biggest mistakes you can make when using LinkedIn's InMail:

Lack of personalization.

In 2017, the notion of taking a generalized approach to marketing is well and truly over. If your recipient gets any sense that you're using InMail to send the same generic message to a group of people, you've already blown your chance of connecting with them.

Conversely, you'll dramatically improve your odds of receiving a response if you take the time to personalize your message.

Before drafting your message, scan the recipient's entire profile for any interesting details you might mention. Awards, musical interests and favorite sports teams all make for interesting conversation pieces when messaging someone.

Related: What Your Profile Picture Says About You

Additionally, some people's LinkedIn pages have links to their Facebook and Twitter profiles, where they might post less formal content. Scan these profiles too so that you get a better understanding of their personality, hobbies and interests.

Be sure to mention any commonalities, such as a shared acquaintance, and use the pronoun "you" to make your dialogue sound friendly and conversational. Statistics show that referencing a former employer in common increases your chances of getting an InMail response by 27 percent.

Of course, it's not possible to personalize every message, particularly when you're targeting larger audiences. In these cases, remember to use the %FIRSTNAME% function and to use terminology that resonates with your target demographic.

Underwhelming subject lines.

A study on email marketing revealed that 33 percent of email recipients open emails based solely on the subject line. If you fail to capture your recipient's interest with the first thing they read, your carefully crafted marketing message is going to be completely wasted.

Mentioning a shared acquaintance in the subject line is often effective, as is communicating a shared interest. If you happen to be members of the same LinkedIn group, then definitely mention it -- this will increase your chances of receiving a response by 21 percent.

The best subject lines have an immediate, emotional impact and encourage a person to read more. If you mention a person's pain points and allude to how your product or service can alleviate them, put that in your subject line.

LinkedIn's InMail has a split testing functionality. I highly recommend you test the subject lines and email copy of your campaigns to get the best results.

Excessive self-focus.

If you're running an InMail campaign to promote a free webinar, for instance, don't spend your limited time discussing your company's rich history and the key things that'll be taught. Instead, focus on how your webinar will actually benefit the recipient.

People are inherently selfish. This isn't a bad thing, it just means that our attention is heightened when we think we're going to gain something valuable -- or conversely, when we fear we'll miss out on something valuable.

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By focusing on the life-enhancing, tangible takeaways that a prospect will receive from attending your seminar, you'll have a much easier time connecting with them.

Talking about yourself and discussing features instead of benefits will not lead to good results.

Sending InMails at the wrong time.

Since LinkedIn is typically associated with work (compared to informal social media platforms like Facebook), people don't login as much during the weekend.

In fact, LinkedIn states that InMail messages sent on Saturdays are 16 percent less likely to receive a response, compared to those sent during the workweek.

Between 9 and 10 am on a Thursday is the ideal time to send an InMail. On Friday, people are already thinking about the weekend, so response rates are typically lower.

Poorly optimized landing pages.

Unlike Facebook ads, where you can specifically target mobile or desktop users, sponsored InMail campaigns don't offer this distinction. For this reason, you've got to make sure your landing pages work well on all types of devices.

Further, make sure your landing page in consonant with your InMail message, both in terms of tone and offer. Adding a countdown timer to your landing page can dramatically improve conversions by creating a sense of urgency to make the purchase then and there.

Customer reviews are another important element to include on a landing page for social proof. You may want to include an FAQ section to alleviate people's fears.

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Don't assume that your landing pages are optimized. Use a tool like Inspectlet to see how people interact with your landing page, including where exactly visitors are looking and clicking on your landing page in order to optimize it for greater conversions.