Google seems understand very well that things and used it well too when launched Google+ service with an invitation only. People are going crazy for a Google plus invite in early weeks of its release.
Unfortunately this situations is exploited by some peoples who are not responsible. Mostly done by spammers and some professionals to make their business out of it. They are creating a fake email template which exactly resembles the invitation email of Google Plus and they are sending the fake invitation email to random users from an email list they bought.
Here is how the fake email invitation of Google Plus looks like [courtesy: Naked Security]:
Usually when you clicked on the "Learn more about Google+" you'll redirected into Google+ page to start use it, but in this case, you will not go to any Google Plus sign up page. Instead, you will land upon a spam website which either sells cheap Viagra, pharmacy products or other random stuff that the spammer wants to sell. Here is one such example site:
You might not believe me if I tell you that some users are really novice and new to the internet trapped by this crap. But really happen. Maybe they think that they need to pay something for signing up into Google Plus from that website and they might end up buying those bizarre products. Until they realized that they have been fooled and looted.
So please, remember and spread this: No one needs to pay a dime for a Google+ account!
Another way to lure users into spam sites and take advantage of the buzz about Google Plus is using video on YouTube. The person who uploaded the video claims has some sort of "Free key", downloading which will give you a free Google+ invitation right away. Here's the screenshot:
See the link at the bottom of video? If you clicked that shortened link you will land on a typical survey site, as shown below:
DO NOT trust with any claims from that page like if you complete a two minute survey, you will be able to download a "Google Plus key". It's 100% fake! Google+ doesn't need whatever key to sign up or log in to its service.
Keep yourself away and tell as many friends as possible that these are spam sites which should be avoided at all costs. You also need to kept out of people who are try to selling Google+ invites.
Please be aware that Google+ is absolutely free and although need invitation, its all because of Google+ is still on beta release. But there is no need to buy invites. You can test our FREE invitation to Google+ here.
Be careful!