It appears to occur where all 11 Google ad spaces are not used up by the competition for that term. This may be occurring where, in the first example, DiscountVouchers.co.uk has broad matched ‘hollywood bowl’ and not negative matched ‘hollywood’ and they are therefore appearing as a related search. Alternatively, they may have negative matched ‘hollywood, but Google may be overriding negative matching as they are pulling in the search result for ‘hollywood bowl’ as denoted by the ‘Related to…’ title. Most worrying, is if DiscountVouchers have exact matched ‘hollywood bowl’ and are not at all bidding on in any way ‘hollywood’, yet Google is deeming ‘hollywood bowl’ of potential interest to a ‘hollywood’ searcher and therefore including a result for ‘hollywood bowl’. DiscountVouchers may see traffic increase (irrelevant traffic) and also CPCs increase up to their max bid since they are appearing on such generic terms. In this case, it’s a way for Google to get your exact matches more impressions and therefore make more money for Google.
This is concerning for advertisers, e.g. an online retailer who sells ‘goth clothing’ and advertises on these sorts of terms may start appearing as a related search on ‘clothing’ (very basic and unlikely example). For a niche advertiser/niche product, this will increase unnecessary and irrelevant clicks and further fill Google’s coffers.
Equally, you may find your CPCs increasing if you are showing as a related search on a more expensive generic term and you may need to adjust down your Max CPCs. I think advertisers need to do a thorough audit analysis of where they are appearing on Google Adwords related searches and potentially consider negative matching the keywords – hopefully that should work, though it may not. Google have not asked permission to do this. I can understand, in some cases, why it might be relevant, e.g. a generic search for ‘Niagara Falls’ probably has paid search ads for some hotels however you may really be looking for tours and so Google suggests related results for ‘Niagara falls tours’ and in this case this new feature makes the ads displayed more relevant to what you want. It is essentially functioning like Google Suggestions however many advertisers will feel their ads are showing in the wrong circumstances. I would be interested to know if Google is using some sort of algorithm to decide who or what sort of businesses appear against which keywords. Also, if there is some way advertisers can stop this from occurring.