Surely the companies in question would very quickly do two things:
1) Kill all of your affiliate earnings.
2) Take the domains off you.
"you will not register any domain names or register keywords, search terms or other identifiers for user in any search engine, portal, sponsored advertising service or other search or referral service that incorporate terms which are identical or similar to ‘Betfair’ or any other trade marks owned by Betfair or a Group Company and you will at all times comply with such reasonable guidelines for the use of such trade marks as may be issued from time to time."