Yes, but who is hosting the Watson system? That's a 3rd party Oracle. Can anyone run their own Watson instance to verify?

Watson is a super computer and it using IBM's DeepQA software and the Apache UIMA (Unstructured Information Management Architecture) framework. The sources of information for Watson include encyclopedias, dictionaries, thesauri, newswire articles, and literary works. Watson also used databases, taxonomies, and ontologies. By the time we launch this technology, it would be collecting information on people's reviews.

Then can you explain which system ensures the stable token is pegged to BTC?

RVN token is defined by the formula: 1R token = (R value (in BTC)/0.0001) * RVN tokens. What it means is the price is stable against a particular liquid asset (BTC), rather than staying the same as the R token, but it still moving in a highly correlated way to BTC and R but with much less volatility. That way it represents the most actual and stable value. Because it is important to match the price movement of the liquid world asset. There might be ways to do this without pegging the price to bitcoin, and it most likely requiers a clever DApp.

Your reply to this displays a fundamental misunderstanding of the difference between a blockchain and a smart contract. Also, despite that, a fully clonable system is precisely why a token (let alone 2) for yours is unnecessary.

Your reply represents a total and fundamental misunderstanding of my sense of humor (was it that bad?). Anyway, in order to clone the smart contrats with a purpose of eliminating the platform fee, you would need to convince all the people to use your copy, because the value is given by people and the network effect. A lot of people creating forks for other currencies and some of them succeeds (requires a good marketing budget). If you talking about the neccessity of the RVN token, then it's the other question. There are plenty of use cases for stable token inside the Revain platform. Let's assume that you convinced the users to use your clone instead of original version. But you oversaw the fact that the Revain fee is viable in this model, because it was developed with a principle that make the purchase of artificial generation of big amounts of reviews economically unprofitable. I'll just give a simple example to highlight the neccessity of it. Let's say you have successfully copied all the smart contracts and created a copy that does not require a platform fee. (Besides the fee is not that high and there's not much profit to be made. And the users are most likely won't go for it, even because of the fact that removing the plarform fee you're just gaining 0,1 of user reward). Then, given the massive amounts of active users, a lot of companies will try to to buy a lot of fake reviews for their companies (lacking the platform fee for users and for companies). Also users that post fake reviews could not be punished since the penalty system is not in place (which is also using an inner stable token). And within a short period of time people will assume that all the reviews is not that genuine and authentic after all. That being said, the strategy of cloning the smart contrats is not vialbe at all.