Does advertising help with your Search Engine Ranking? At one time paid links use to count as a quality link, and although there is still some good link juice there, it is not what it used to be.
Advertising is a great way to get a quick boost in traffic, but it is not going add much to your SEO score.
If you want your site to be successful, having a valuable web experience for your customer is going to be a high indicator of your websites value. When a search engine sees people staying on your site for a good amount of time and more importantly returning to your site again and again it is going to show the value your website has.
Small things can really make a big difference.
Show you are an expert in your niches, a good way to do this is by keeping a blog and showing the search engine how visible you are to the world. Blogs get ranked easily because it shows the search engine a high structured set of data and new content that gets updated regularly.
Search engines like structure and another way to give the search engine what it wants is with a site map. This will make it easy for the search engine to index all your pages. Make website updates regularly and be sure to include tags.
Of course you never want to keyword stuff, but make sure you use keywords that indicate to the search engine what your site is about. I would recommend you stick to about a 5% keywords density.
Do not forget about onsite SEO, doing everything correctly can make a huge difference in your SEO efforts.