The maximum time is 10 minutes but we recommend 1-3 mins for better engagement and reach.
5. Don't post links in the description
When you write a post or create a video, add as much value as you can but don't add a link to an external site. LinkedIn will see this as an attempt to take users away from the platform and it will downgrade the reach of the post.
Well here's a workaround. LinkedIn doesn't downgrade the reach for any link in the comments section. This wouldn't be fair as someone else might link to something in your comments and affect it's reach.
You can use this to your advantage by adding any third party links relevant to your content in the comments. Just mention it in the post and users can follow the link from the comments without affecting the reach of your post.
6. Post at the right time
Posting at the right time is important for gaining initial traction on a post. If no one engages in the first few minutes or hours your post is in danger of being marked down on value. Think about when your audience is going to be active on the platform.
This might not be during the day when everyone is busy, often people are using LinkedIn in the hours before and after work or during lunch time. Even the weekend might yield some results.
You should use your common sense for this but also test different times as networks always differ (if you're network is freelancers or people working from home their work hours will be more flexible).
If you follow all of these tips you'll see a substantial increase in your LinkedIn engagement. Ultimately LinkedIn have designed their algorithm to make the platform interesting and useful for their users, and to keep them on the platform for as long as possible.
The most important thing you can do to increase your visibility is understand what LinkedIn is asking for, luckily this is the same thing that your audience is asking for. So by providing valuable rich content and conversation you'll be hitting both targets at once.