When I first add keywords and bid to my campaign they all where active.But now slowly they are becoming inactive. Is it a problem with the quality of my landing page ? How can I increase my quality ?
If they are just raising the bid minimums a little bit, then it is the combination of low bid price/low CTR. CTR is the most important aspect. If they are setting your minimum bid to $5.00 etc, then it is a slap. Your landing page quality is a factor, perhaps the factor. Relevence is the key. Tight ad groups with core keywords in the ad title, text, and on your landing page will win the day.
Making more keywords related to my niche in Titles,Meta Tags and Content of my landing page works for quality ?
Maybe, but more adgroups with fewer keywords is more often the solution. I used to think people talking about he ultimate being one keyword per adgroup were crazy, but I'm beginning to believe them. Page should probably only have a few keywords on it, and all should be closely related. Too many repetitions can work against your quality score.
No I think that keyword density is not a factor within adwords. But having some keywords in the title and content can't be bad for your QS.
if you are experiencing the slow decline of performance within you account and keywords becoming inactive there is only 1 problem that needs to be solved. That is your text ads CTR or click through ratio... run 2 - 3 text ads simultaneously for every adgroup. every 3 - 7 days drop the worst text ad and write a new one. Eventually you will see you account QS rise. You can find you QS within each adgroup under the keywords tab. when you are on the keywords tab if you do not see the QS column you need to click the hide/unhide columns link and activate it