I've tried LinkedIn, couldn't get my head around it. I found their UI to be far too fussy for what I wanted and the site is just plain ugly to look at. The amount of email updates you get from it if you join a couple of groups too is utterly ridiculous!
I think the way LinkedIn is set up is purposefully designed to prevent people JUST looking for potential clients. It is obviously mostly for networking and sharing ideas/info, but it can work if you do it carefully, target the right groups, etc. Start by answering a few posts and then posting your own questions, not diving straight in with "this is me, you can hire me".
I trialled out Linked In's Advertising for a short period but wasn't impressed. It's basically a pay per click service but I was tempted by the fact you could target where you ads are displayed by sector, persons job titles etc. In theory this would be great, in practice its very expensive. You have to set your CPC at a min of Â£8 a day with an average click cost of around Â£1.60. It seemed every time I set the campaign off it would reach the daily limit in about an hour and looking at my google analytics either no clicks, or a lot fewer were registered. I put in a query to their support and just got palmed off claiming the issue must be with google analytics or all the users must have cookies disabled. Whilst I think it's unlikely that Linked In would be running a blatant scam, as they can offer no proof that these expensive clicks happened I've knocked it on the head.
From my experience, it looks like LinkedIn is great in providing job opportunities, if you are looking for an in-house position. I have never had the feeling of a platform thought for pushing freelance work.
If you want to get more clients from LinkedIn then you can use the following tips:
Create a complete and a strong profile then ask colleagues for recommendations. These recommendations are a form of social proof that provide your potential new clients the feedback and actions of others to determine if they want to work with you.
Publish contents to gain visibility in-front of the audience
Join LinkedIn groups
Use LinkedIn advanced search to search queries for people or jobs related to your search terms.
If you want to get clients form linked in first you need to have good linked in network, if anybody posted about their project requirement you need to communicate with them like this way you will get clients from Linkedin.