One critical problem that could ruin your Quality Score – and your Google AdWords campaign.
It’s of critical importance that you maintain a high Quality Score for your AdWords campaign. It will make your campaign far more cost-effective.
However, if your website has malware or viruses on it, your QS will be penalised heavily by Google. And so will your SEO.
To make matters even worse, I believe you’ll be penalised if other websites (from other companies) on the same shared server, contain malware or viruses .
The major problem with this is that you won’t even know the problem exists. As far as I can tell, the only way round it, is to ensure you use a quality hosting company.
But, be warned, separating vendor’s marketing hype from reality is no mean feat.