Prevent? -- impossible, but you can make it harder.
Disincentivise? -- possible, but you won't like the answer: provide bulk data exports for interested parties.
On the long run, all your competitors will have the same data if you publish it, so you need other means of diversifying your website (e.g. update it more frequently, make it faster or easier to use). Nowdays even Google is using scraped information like user reviews, what do you think you can do about it? Sue them and get booted from their index?
