A "low price" depends on what you consider to be a low price; this is very subjective. However, I will try to shed some light on the subject. If by low, you mean something like "$50 per month" or "$500 per year" it's because they are either doing no work and charging you a premium, or they are using methods that will hurt your business. Low prices sound great, but if you factor in the costs of doing business, the hourly rate, etc. it is impossible for any company to do an effective job for "$50 per month." For the average client, it takes about 1-4 hours per week for proper search engine optimization. This equals to 4-16 hours per month on average. So if they are charging you $50 per month, I promise they are not doing anything, or they don't know what they are doing. So, are their rates really that low, or are they simply a "supply and demand" business; you want the service, they are offering it. That doesn't mean they will perform the service, and since it's difficult to track what is being done, you might never discover you are being ripped off. Do a search for SEO and find out what the search engines have to say on this issue so you can avoid a costly mistake. I am not trying to put down SEO providers, but in my experience, 90% or more do not know what they are doing, and don't really do the work they say they are. As a consultant, I have found this to be true in every case.