One thing I've thought about but never had the chance to put into practice would be to randomize CSS classes and IDs. Most web scraping relies on these to identify the content they are looking for.

Imagine if everyday they changed? It would make things a lot more difficult.

There would be disadvantages to actual users with this method like caching wouldn't work very well but maybe this alternative site could be displayed only to bots.

The crawler could get smart about it and only use xpaths like the 6th div on the page so maybe in the daily update you could throw in some random useless empty divs and spans in various locations.

It's a lot of work to setup but I think you would make scraping almost impossible.