Impressions and clicks going down suddenly

can anyone tell me the possible reasons

[Alam]

There is a sudden drop in number of impressions and number of clicks across all my campaigns & ad groups since April 18. I haven't changed any settings, bidding or creative. In fact there are no changes made over last 2 weeks. Till April 17th everything was going well. But suddenly from April 18, things are going worse.

The drop is of 50-60 clicks a day and that's significant for my business.

Can someone tell me the possible reasons.

[Sujan]

One word: competition.

- Jan

[Robsp]

The new pope costed us quite a few clicks :)

[petra]

I noticed the same and so I increased my bid.

[ucdawg12]

I have had a similar thing happen to me but it started yesterday. I'm still the only ad that shows up and my average ad position is 1.0 as it has always been so I know it isnt competition.

[sem4u]

It could be due to a change in the SERPs. Google is testing all sorts of things these days, and it may be that users are clicking on regular/local/froogle/image results instead of the sponsored ads.