- Shadow domains — affiliated websites created by SEO firms that redirect traffic from your website to theirs. Owning the rights to the site, the SEO may choose to sell the shadow domain to another website owner, effectively using your money to help advertise someone else's site.
- Doorway pages with links to other clients. Practices such as ranking guarantees, address bar keyword sales, and placing links to your page in the advertising rather than the search results section of a page.
- A list of clients the firm has worked with in the past, and a few samples of their work.
- The extent of the firm's experience in your industry and area.
- Whether the firm provides any additional services outside of SEO, such as strategies or consultations.
- The level of communication you can expect from the firm while working together.
The key is to find a quality SEO firm that is dedicated to improving your site, not to siphoning money from you. Once you find the right firm, your site views could increase immensely, and faster than you can click your mouse.