I have been using adwords for a while now, about a year. Just recently, in one of my adgroups, i've seen the minimum bid for a certain keyword jump up to a value in pounds, rather than pence. The quality score has dropped to poor, when it was previously either great or OK. I rarely ever see a poor quality score, as the landing page has been done to ensure it is relevant to what the user is looking for. I have good history with these keywords in terms of CTR etc, so don't think this should happen.
I think more advertisers are now bidding on said keyword. One thought is that one or some of them have just raised their bids very high, although from what I understood is that Adwords nowadays is not about just bidding as high as possible to get the desired ad position.
Can anybody share any thoughts?
Many thanks