I had a few keywords that usually received maybe 20-30 impressions a day and a couple clicks. Then it suddenly rocketed up to several thousand impressions a day without any more click throughs. Could someone be performing artificial searches for the sole purpose of ruining my click-through-rate? Thanks.
I doubt it. Check you account or campaign to see if it is set to Advanced Match. I have seen this happen with the Advanced Match before.
There can be a case in which a high traffic website have started using ads from that day. Its highly suspicious activity though.
It may not be that at all. It could just be some event where people use your keywords more often because of the event. Here's a real example. A few years ago, a client in the kids clothing business was selling a brand called Charlie Rocket. Not very many searches for that brand, normally just a few each day. One keyword used was simply "charlie rocket" in both phrase and exact matches. Well, there was this guy called Charlie Rocket from SNL who died one day and the impressions increased 100-fold. I was not aware of this guy but you can see how an event can affect your impressions (and click rate and QS) if you don't use proper keywords. Of course, the keywords "charlie rocket clothing" or "charlie rocket brand" were not affected. Did make me scratch my head however for a while. So it may not be someone (thousands of times?) searching over and over on your keywords. Do more research on the keyword in question. What happened recently that would cause this jump? Even if you find out, the event will have died down and it will be too late but you can protect yourself in the future with some negative keywords. I used died, death, comedian, funny guy and snl in my Charlie Rocket group. No problems since and the campaign has improved.