Before anyone is going to give you the time of day (let alone their money), requires you to give them something first. It's long been known that 'Reciprocity' is a powerful way to influence people - and you've probably heard the phrase 'give to get'. This is particularly the case on LinkedIn.
Freely give help, advice, your time, expertise, tips, ideas, links, access to resources - and so on. And slowly but surely people will see that you genuinely do care about helping people.
Givers get more in the long run.