I know you can block semrush bot with a plugin called linkprivacy. All it does is stop tools from crawling your website. Not sure if this will help you with adwords or not.
It won't, and this issue is a huge one for those of us in the lead generation industry.
To be honest, if you're using Adwords right now and are looking to stop competitors clicking adverts and discovering how you earn your money follow these rules:
1.
Block your site completely from Google by using robots.txt + meta tags - This is especially true if certain pages / text on your site could identify what affiliate / lead gen network you're using like custom privacy pages or terms and conditions that contain certain statements required by the merchant.
2.
Try to steer clear of head terms - Head terms convert terribly and are typically the first port of call for click happy newbies and "SEO professionals" looking to scope the competition.
3.
Use a separate website for testing - Your testing website will almost always be bidding on broad match keywords, hence it's often the one that will be picked up by SEO experts, brand managers and other affiliates. It's also the one people will probably test Spyfu against to try and figure out how your getting your conversions. By
only testing using this domain you'll always be throwing people off the scent by bidding on useless keywords. When you've found a profitable subset of keywords, add them to your negative list for the testing site and create a new campaign for your main conversion site - and always try to either use phrase match, exact match or try to bid just enough on a broad match to make a profit. You want to minimize your exposure to having the main sales website discovered, especially if you've worked hard to find the perfect design to promote your conversion rate.
4.
If you're in a really competitive niche, switch up the sales site frequently - This is especially true to certain financial and compensation niches, competitors especially other affiliates will use Spyfu to try and figure out what keywords you're bidding on. By changing your sites every 3 months you'll keep them off the scent.
5.
Private whois - Always use a private whois. Competitors will try to look for the links between brands, websites and company names.