Some agencies specialise in only SEO or link building whereas other large consultancies can provide end-to-finish packages from creating or redesigning your website to ongoing SEO maintenance. Here are five of the key SEO services that you should look for when evaluating on-line marketing agencies.Keyword researchCreating your keyword portfolio is one of the most important SEO services offered by agencies and the foundation of your on-line marketing campaign. This is best conducted by a professional trained in keyword research. A specialised SEO company or consultant will use different techniques to find the best keywords for your site. This might include client and customer feedback, keyword research tools, competitor analysis, social media and so on.SEO methodsAn skilled SEO consultant will assist you map out an SEO strategy (on-line and offline) that drives visitors to your site, increases the conversion rate and provides you the highest return on your investment. The keyword research (see above) and technical analysis of your site types the basis for your campaigns so that a complete marketing plan can be mapped out in order to start implementing the SEO activity.Link buildingWhen you are researching the SEO services that you need, ask the consultant or agency about link building campaigns. Search Engines see a back link to your site from other credible, trustworthy, authoritative and relative websites as a validation for your website. A professional SEO company should have developed a network of contacts, established relationships with webmasters and know how to find the very best link building opportunities.SEO copywritingCopywriting is an additional of the SEO services that a larger agency may offer. Off page and on page optimisation is crucial to your SEO campaign but it is not usually the first click that you need to worry about, it is the second one. The distinction between a high or low bounce prices might come down to the quality of your SEO copywriting. An SEO company will help you find a balance between keyword-rich copy and engaging copy that encourages conversions.SEO web designThis can be one of the most vital components of your campaign and yet one of the most neglected SEO services. With new websites, SEO consultants should ideally be consulted at the start of the process when you are deciding on a technical platform, a Content Management System (CMS), shopping cart software or other key design components. Sadly choosing the incorrect platform can have severe implications on your potential SEO success.