What factor will affect the Quality Score?

I know there are numbers of factor that will affect the quality score. Here are the factor that i know

Campaign history
Campaign Name
Title and description in ads
landing page relevancy with ad

What other factors that will affect the quality score?

Campaign name doesn't affect QS.

Account history affects quality score. Also, display URLs have some mind of quality score history. This way creating a new account and using the same display URL does not guarantee better quality score (if your current quality score is poor).

Also, I'd say landing page speed. That's why they say you want to host your site with a fast & reliable hosting provider.

And the major one is average click through rate. Google guys gave us a presentation couple of months ago (I work in PPC) on QS. Basically, you should always try to maintain your average CTR above 1% as avg CTR below 1% will always affect your QS.

About Quality Score

A Quality Score is calculated every time your keyword matches a search query -- that is, every time your keyword has the potential to trigger an ad. Quality Score is used in several different ways, including:

influencing your keywords' actual cost-per-clicks (CPCs)
estimating the first page bids that you see in your account
determining if a keyword is eligible to enter the ad auction that occurs when a user enters a search query
affecting how high your ad will be ranked
In general, the higher your Quality Score, the lower your costs and the better your ad position.

Quality Score helps ensure that only the most relevant ads appear to users on Google and the Google Network.

Most of the quality score is based on how you optimized your content to this specific keyword.

The second part is more based on users behaviors if they click often on your ad or not, how long do they stay on your website, and bounce rate.

Campaign Name

As Jagelski said, campaign name has no effect on QS. It's a good idea however to properly organize campaign and group names as it makes management easier. May not be an issue with just one or two products but try a dozen campaigns with a thousand goups.

Campaign history

No. It doesn't make sense for one. There's no evidence that campaign history has an effect. I've taken many poor QS campaigns and bring them up to respectibility and ofen QS of 10 many times.


Factors Affecting QS

CTR, about 65% of QS in Adwords. Search engines want quality. So how do you measure quality? Votes by the seachers. The reasoning is, if an ad has a higher CTR, it has higher quality.

Relevancy, about 25% in Adwords. If you sell dog food, your landing page better be about dog food, not cell phones or anything else.

Other factors, obviously about 10% left. Google has stated that you landing page loading time will affect your score. Whether it's the whole of that 10% or just part is unclear. Some say having a policy helps. Maybe but doesn't hurt to have one.

QS is a relative number and measures how good your CTR is compared to others using the same keyword. The mean is 5. So if your QS is 7, your CTR is above average. It doesn't matter what your actuall CTR is or your position because your CTR is normalized to your position. I've seen QS of 10 in all positions and for any CTR, even below 1%. Stop thinking in absolute terms.

QS influences your position (along with your bid) and what you actually pay.