Quite often if something isn't fully understood, it can come in for criticism, also it doesn't matter how good a thing or person is, there will always be a percentage of detractors.
I have a free account with LinkedIn and initially I found it a bit perplexing and wondered whether it had any use at all. I gained absolutely nothing from it.
Over time I explored a bit more and became acquainted with the various groups. I decided which groups had any relevance to me, checked whether the groups I was interested in had a decent number of members and joined the better populated ones. I subsequently posted in the relevant groups and found that I received a lot of interest and subsequently got business. I also gained some contacts. An amazing turnaround for a bit thought and at zero cost.
Once you are a member of a group, you can request a connection from anyone in that group. You simply tick a box to say that you know that person through the group concerned.
I have received spam, but it has been hardly worth getting bothered about. I'm sure if spam did become a problem, there is a reporting mechanism to deal with it.
I would suggest only linking with people who may have a use for your business or vice versa.
I have a Facebook account and find LinkedIn nothing like it at all.
I have a conveyancer/stamp duty mitigator friend who makes a point of ringing each contact. She finds this a far better approach than using written communication and as a consequence, she gets more business.
My LinkedIn public profile URL is: Brian Abbott - United Kingdom | LinkedIn
if anybody sees a beneficial reason for linking, please do. If you choose the 'I know this person option' (or words to that effect), you need to put the person's email. Mine is abbbrian+linkedin AT