Google AdWords can return great ROI on onlne marketing spending, but campaigns need to be setup right and monitored closely during runtime. Here are a few tips that might be useful;
- Keep an eye on your Quality Score; low QS leads to higher required bids.
- Relevance is key, so split your most popular keywords in separate Ad groups and use these keywords in your Ads, as well as on your landing pages.
- Split campaigns for Google Search and the Google Content Network; their workings are completely different.
- Don't measure succes on clicks or CTR, but on Conversion Costs. So install conversion codes on your site.
- Link Google Analytics to your AdWords account. Check quality of traffic on bounce rate as a start.
- Look at order/lead logs for time trends and experiment with Ad planning to spend your budget more targetted.
Just a few loose things, there's really a lot you can get from AdWords if you have tiem to digg into it. Otherwise consider hiring an expert; as long as you know the basics you can calculate yourself if outsourcing is viable. If an expert can decrease costs and raise conversions, his fee may be very well spend.