But if the percentage of invalid clicks in your Search campaigns suddenly shows a sharp increase, buckle up—it’s going to be a rough ride. In a recent case with one of our clients (average CPC > €10), we closed October with record-breaking results, and then suddenly what you see in the chart happened. Not only did we reach nearly 80% invalid leads, but despite the refunds issued by Google, the campaigns have been off track ever since, and their performance has plummeted. After several complaints (pro tip: complain, complain, complain, and complain again!), Google gradually increased the percentage of invalid clicks, but despite everything, the performance of the affected campaigns is still much worse than before the attack, which suggests that there is still a significant amount of fraudulent clicks that Google is not detecting.
On the other hand, the extremely linear rise in the percentage of fraudulent clicks might indicate that the attack was meticulously planned… or that Google, in the first few weeks, had no clue, and only started detecting the bulk of the attack in January. The latter could happen if Google only detects and investigates duplicate clicks after they reach a sufficiently high number within a given time frame. The idea of a slow response from Google, with some tolerance for the first toxic clicks, remains just a hypothesis, since Google’s anti-fraud algorithm is a black box, but it would explain that straight line in the chart starting in November.
Beyond filing complaints, what you can do is try to identify on your own the keywords, search terms, devices, and locations that have shown anomalous behavior since the start of the attack, so you can exclude them, or, if you’re using manual bidding, significantly lower bids on the terms, locations, devices, and audiences under suspicion. Some signs that may indicate such activity include a sudden increase in click-through rate (CTR) accompanied by a drop in conversion rate; a drastic increase in bounce rate or a significant decrease in time spent on your website or landing pages; an increase in PPC visits from locations outside your targeting; or a significant volume of clicks coming from a single location, such as one postal code or a narrow geographic radius.
If all fraudulent activity is coming from a few IP addresses, one option is to block those IPs, but we only recommend this in extreme cases, temporarily, and as a last resort. Nowadays, the use of dynamic IPs is widespread (making the blocking of a toxic IP short-lived), along with CG-NAT, a solution used by ISPs that allows dozens—or even hundreds—of customers to share a single IP. Because of this, in trying to block a few toxic users, you could end up blocking thousands of potential customers for your business.
If you suspect a specific competitor and their office is not located in the center of a large city where the population includes your potential clients, you might consider “turning off” a 1km radius that covers their location. It’s a bit of a hassle, because Google doesn’t allow you to directly exclude locations in search campaigns using coordinates and a radius, so you’d have to work around it: (1) define a positive location with a 1km radius that includes your competitor, (2) set a bid adjustment of -90% on that circle; and (3) use manual bidding, because otherwise Smart Bidding will ignore the adjustment. If you think switching to manual bidding would be worse than the problem you’re trying to solve, exclude the entire city, duplicate the campaign, and in the new one, target only that city, this time using manual bidding and applying the -90% adjustment on the zero zone. It’s not ideal, but in extreme cases…
Note: if you’re using 1km radius locations to avoid competitor clicks, keep in mind that the circle doesn’t have to be centered exactly on your competitor: it just needs to include them. In fact, try centering it on the least populated area around them. For example, if you suspect a competitor working in Mercamadrid is clicking your ads and you want to avoid that, a circular location around Mercamadrid would also exclude people from Vallecas and Villaverde. It’s better to shift the circle southeast, where it’s more sparsely populated, so it covers all of Mercamadrid while affecting as few potential clients as possible.