Question
We are building a marketplace where tourists can get advice from travel bloggers.
There are a few modes of monetization we are exploring. One of them is a monthly membership to the platform. So, on our side, we are building a website, iphone and android app. The customers are charged whenever they want to have a conversation with the experts just as in "Clarity".
Answer
You can use web sites such as Kickstarter to "pre-sell" memberships just like is done for other such products. For the "pre-sell", you may want to offer a special deal for being an early adopter.
There are also other sites, such as Fundable, that seek financing for the business.
Let me know if I can be of any further assistance.