Decreasing QS On Keywords

I've been refining my campaign as I've been learning and have found my QS dropping on a couple of my Keywords. They are dropping from 5-6 to 4 and getting bumped off page 1. What can cause this? The content on my page has remained the same (relevant to my keywords), I have adjusted from broad match to phrase and exact match's and have optimized my ad text. Could it be because of my poor CTR, bids are too low or has Google just reevaluated the relevance of my sites content to my keywords?

The diagnostics tool suggests increasing my bid but I don't see how that would boost my QS.

Any advice is greatly appreciated.

 

Improving QS through landing page optimization is relatively hard, since it requires content writing, R&D etc.

Still it's very important, but in order to simplify things let's say you want to maximize your keywords' QS only through campaign optimization actions.

Try to go over the search terms (under "See search terms" drill-down box under Keywords tab). Perhaps you'll find a few with significantly lower CTR.
Exclude the under-performing search terms insert them as negative-Exact, and even better: negative-Phrase (carefully with the latter).
This can improve the ad group's CTR, and consequently, its QS.

Think of it as if Google is comparing your ad's CTR and position to the ones of your competitors on the same impression.
The impression is per search term, not keyword. A given search term triggers a keyword on your account. Assumng you have phrase and broad match keywords, it might be that your ads are missing the user's intent when he typed his search term, i.e. for some impressions you're targetting the wrong audience.

In addition , the usual:
Tighter ad groups, constant ad optimization yada-yada-yada...

 

Improving QS is not about improving landing page. It's about improving click rate. Increasing bids does not increase QS. The two are not related. You are being asked to increase bids because, given your QS, you are not showing on the first page. Ad rank is calculated by multiplying bid and QS. Read more in the Adwords FAQ.

So what's happening is, your CTR is lower than the average CTR achieved by all advertisers for that keyword. Your quality is poor compared to them. In other words, your ads are not attractive and getting people to click.

Note that the keyword relevancy portion of QS is 25% of the score. If you're relevant, good. Work on improving click rate. If not, remove that keyword. Also note that QS takes position into consideration. Saying "low CTR" means nothing. It will be lower comparatively in lower positions. QS is telling you how you compare to others at that position.

 

click rate is dependent on ur ad conversion is on ur landing page