I've noticed online networkers have become much more aware of people who look at their LinkedIn profile during the last few months, but frankly not many do anything and let potential opportunities slip by - perhaps for the fear that they don't want to appear too pushy. I suspect there's something very British about that, but I admit that's a guess (wouldn't it be fascinating to see the LinkedIn behaviour stats country by country?).
To be fair, the one thing to avoid is being too much of an eager puppy, shouting "look at ME!!!....LOOK AT ME!!!!!!" That will scare off the most hard-nosed of individuals. Nonetheless, there's still some good ways to react and not have people look over the top of their glasses as you and mumble 'Jerk!' as they turn on their heels and run for the safety of a dark corner.
Firstly, remember people are likely to look at your profile for a reason. Most LinkedInners don't cruise around just because they have a loose five minutes to fill until their next crisis. They might be looking at you as a supplier, as a potential old friend, as a partner, or even with a job opportunity. For example, this morning I viewed over 30 individuals for 3 searches I'm working on right now. I'll be surprised if more than one of them reacts, but I'll bet more than half of them know I've looked.
My best advice is to respond with something quite neutral, but professional. How about?.......
"I noticed you reviewed my LinkedIn profile earlier. If there's anything of mutual interest you'd like to discuss or explore, please feel free to make contact. Otherwise, many thanks for your interest, and best wishes in your future endeavours"
It's short, polite, professional and you look like you're interested. You may find the style a little dated, but to my mind it might mark you out from the rest of the rubbish we all get from time-to-time. I've used this many, many times. I've never had a negative response, and I've expanded my network and started some relationships that remain active.
You'll lose nothing and may gain something. Don't let things just drift by. That was NEVER a good policy.
I have a general views that the principles of the DUMB approach are very sound (no job is so simple it can't be done wrong).If you want to see more DUMB advice.............