I don't know it's just me or everybody facing this problem but here is my case: At first, I used root domain as landing page and run an Adwords campaign. The QS is around 7-8. My ad rank was at the 1st position for the most competitive KWs (I bid really high). After that, I noticed that the bounce rate is too high (70%), so I decided to change the LP from my root domain to an inner page, also, I changed the description line 1 and 2 to make it more compelling. The new landing page (inner page) was written with Adwords optimization in mind, besides that it was more informative compared to the old landing page (root domain). In fact, after the change, the QS still remained around 7-8, no significant decrease or increase in QS. But the problem was that, my ad rank decreased from 1st to 4th ! Some other KWs decreased from 1st to 10th. Is this a normal fluctuation after changing LP ? Will my ad rank re-claim the 1st position again ? Notice that, I have not changed the bid, the max CPC still remains high.