Blocking other engines in robots.txt

[Romancing]

If your primary target of business is not in China is their any benefit to blocking Chinese search robots in robots.txt?

[RyanKent]

I don't see any benefit to blocking search engines with robots.txt with the exception of Bing or Google as necessary.

Robots.txt is strictly a suggestion to those crawlers who care enough to respect your wishes.

The only benefit it can offer is IF a crawler chooses to respect your wishes, then your site will have a bit less traffic volume during the crawl. The reality is any specific crawler from one of the many random companies is going to visit so infrequently it wont make any noticeable difference.