Lately, it seems like there has been an increasing number of product/service launches taking a “slow launch” approach. Instead of a one-stage en masse introduction, these slow launches are often by invitation-only.

The example that everyone is talking about lately is Google+, which, for the sake of simplicity, we’ll call a social network/sharing “project.”

Google Screenshot

Google wised up after the lukewarm response to its Google Wave and Google Buzz launches. Rather than open the floodgates to droves of enthusiastic users when Google+ launched on June 28, Google opted to slowly invite a controlled number of users. As we all could have predicted, this “exclusive” approach fueled public demand for the service. In fact, on June 29, Google’s Senior Vice-President of Social, Vic Gundotra put out the following post in response to the red-hot public reception of Google+ after the site had been live for mere hours:

“We’ve shut down invite mechanisms for the night. Insane demand. We need to do this carefully, and in a controlled way. Thank you all for your interest!”

We love exclusivity and hate it … depending on whether we’re among the “included” or “excluded.” I think we can all relate to the famous quote by Groucho Marx, “I don't care to belong to a club that accepts people like me as members.” We aspire to be special, because really, who doesn’t like to feel special? When you attain something desirable, especially if you were previously excluded, you tend to value it that much more.

Invitation-only deal sites like Gilt and RueLaLa had a certain cachet when they launched. There was an air of highbrow mystery and exclusivity for several months that piqued the interest of people who may not have otherwise tried to access the site. Before long, just about anyone could score an invitation, and while these sites are still luxury-focused, now they’re often bundled together with daily deal sites like Groupon.

Activision has reported that more than one million fans of its video game, Call of Duty have signed up for the beta of Call of Duty Elite since the registration site opened last week. I think that name says it all.

Does exclusivity help or hinder the success of a launch?

Do exclusive or invitation-only launches tease and test your patience? Or do you constantly refresh your inbox with the hopes of getting an invitation of your own?

Contributed by Anne Norris. Follow her @anne_norris