This one is easy, but maybe you'll get it wrong. You don't need to know anything about SEO for this.
Guess a number between 1 & 10.
The first 3 people to email me the right answer at firstname.lastname@example.org, gets an invite.
Of course, you need to trust me. But I have the number written down on paper in front of me.
Updated: Only one try per person (please don't use multiple email addresses, I run these contest all the time) and I will announce the winner as soon as I get 3 correct answers. But you need to be the first three, if I get four correct answers, the 4th does not win.
***CONTEST IS OVER*** The answer was 5. If I have time, I'll post a summary of the attempts.