suggestions for free web advertising?

There are many ways you can advertise online for free. SEO is just one way of maximising your exposure online.

In addition to spending effort on increasing your search engine traffic, you can also try the following online marketing methods:
1. free classifieds ads
2. free business directories
3. B2B and B2C business networks (depending on the type of business you are)
4. online marketplace, although you have to pay a commission, the exposure is free.. depending on your profit margin, you might not mind paying the commission if your product is sold
5. blog reviews - see if you can find blogs that specialise in product/service reviews, there are a lot of blogs devoted to reviews, if you can find some, try contacting the blogger and see if they might agree to feature you in a post
6. online press releases
7. social media - virtual word of mouth

advertising for free though certainly time consuming really does boost your SEO and oage ranking on search engines. If you are an Ecommerce site and your starting to make money through these methods, you should certainly look into a low budget PPC (pay per click) campaign through Google, they provide on going reports/stats so you can see whats working and whats not. You have to spend money to make money.