They're a bit vague when describing the "I-was-going-to-buy-it-anyway" problem, but it sounds like they're mainly talking about PPC ads on search engines stealing from SEO links on the same pages. (Some of it seems to be talking about stealing sales from the direct channel, which I have no idea how to handle.)
If your website is already tracking ad performance on a per-ad basis (i.e., tracking all the clicks on that ad, and keeping what you pay per click below what you're getting per click), then optimizing for only the paid search traffic that's incremental, and not cannibalistic, is pretty straight-forward, conceptually.
For a given ad's keyword, instead of optimizing only for the results you get from PPC traffic, you treat your PPC bid as an input that affects sales across PPC and SEO traffic for that keyword, and optimize accordingly.
There are a few extra steps and decisions that need to be made before full implementation, but this is the basic idea. It's actually not too bad to account for.
There are other reasons to advertise in search engines on your branded keywords.
For starters, you have account wide and campaign wide quality scores which impact how much you pay per click across your entire account. Having branded keywords which will have high quality scores can help lower all your costs.
Secondly, your competitors can advertise on your brand even if its trademarked. Owning the top position is cheaper for you and a good idea.
Third of all, You would think a brand would want to own as much of the search results page as possible. It will drive up clicks even on your organic listings.
There are also many case studies that show paid search for branded keywords getting more traffic than just organic listings.
I'll search for a product and amazon all the time. I would just easily buy that same product from Walmart if they had it for less.
Branded search does not mean they will buy from you anyway. It could mean that, but it certainly doesn't guarantee that.
If your website is already tracking ad performance on a per-ad basis (i.e., tracking all the clicks on that ad, and keeping what you pay per click below what you're getting per click), then optimizing for only the paid search traffic that's incremental, and not cannibalistic, is pretty straight-forward, conceptually.
For a given ad's keyword, instead of optimizing only for the results you get from PPC traffic, you treat your PPC bid as an input that affects sales across PPC and SEO traffic for that keyword, and optimize accordingly.
There are a few extra steps and decisions that need to be made before full implementation, but this is the basic idea. It's actually not too bad to account for.