Creating cultural change to sell products isn’t easy. But it has been done been done before. Deodorant, cigarette’s for women, and razors have all successfully created cultural change.

Not wearing deodorant is now considered gross. Hairy arm pits or legs are now considered gross. Cigarette companies targeted women by calling cigarette’s “freedom torches”. All three of those changes were backed by companies in order to sell more products.

There are four main things that go into Cultural Change:

1. Doctors (or a bunch of smart people) must approve it vocally
2. Successful people and people you know must be seen using it
3. Must be a mass consumer product (sold in the hundreds of millions)
4. Mainstream users would say the wrong thing to do is to not buy it

I believe Orabrush, an easy to use tongue scraper, is going to make cultural change happen. I predict in the next 5 years not scraping your tongue is going to be considered gross.

I learned about Orabrush yesterday because my twitter and facebook stream was filled with likes. Here is how they are making it happen:

#1 The person that invented the Orabrush is a doctor and they use “Dr. Bob” in all email communications and on their website whenever they need to establish credibility.

#2 They are getting everyone you know to tweet about it. If your friends are doing it then it is totally okay for you to get one as well. The power of social influence is a big one here. They strongly incentivize you to “follow” and “like” it. Here is a break down of how they are getting a ton of people to follow:

A. On their website they have a call to action asking if you want the Orabrush for free? Yes of course I want one for free.

I got some quick advice from Gary Swart of ODesk and he said the best way to build a marketplace is to make sure the “buyer” and “seller” are the same person. If they aren’t the same person building a marketplace will be very costly and time consuming.

Lets take a look at eBay. Buyer and Seller are practically the same person. You only really need to market to one type of person and both sides of your marketplace grows.

Now for example lets look at Twitter. I joined twitter to just follow a few people. After a few weeks I started tweeting as well. Same thing happened with me on Quora. The “follower” became the “contributor”. You will see similar patterns with StackOverflow, Airbnb, StumbleUpon, and Fon.

If you take a look at ODesk or Etsy (both very successful companies) they both spend a lot of time and money on advertising (Search Engine Marketing in ODesk’s case and Grass Roots Community Building in Etsy’s case).

Conclusion: If you want to build a marketplace make sure you only have to market to one person.

This blog post was inspired by a tweet my buddy Noah posted a few days ago.

Grubwith.us is an easy way to meet new people over dinner. My buddy David Kadavy keeps telling me about how awesome it is.

I also love the way they are marketing the concept. They now let you create your own meals and invite your friends. Pretty similar to meetup.com but instead focused around just meeting people over dinner. Currently the way they make sales is simply word of mouth and press. A customer has to learn about the site (either through press or friends), go to the site, and then sign up.

Now, in the new model they are trying out, they will be getting direct sales from people wanting to throw their own dinner parties. The value proposition for you to do this is pretty high, grubwith.us takes care of splitting the check and figuring out the best menu possible.