Checklist to help you choose a decent SEO company

Given the number of posts on here from people who have been stung by SEO cowboys, I though it might be a good idea to compile a list of considerations - a checklist for non SEOs to bare in mind when choosing an SEO company to work with.
If we have one central repository for these points then it should avoid the same thread occuring time and again, whilst at the same time offering a valuable resource for the end user.
I'll start, please feel free to add your own points:

1. The minimum on-page optimisation you should expect is as follows:

- page title
- page description
- meta keywords (for completion sake only as they have no impact)
- Header heirarchy: H1, H2 H3 etc
- URL
- Body copy
- internal navigation
- alt tag optimisation
- Any decent SEO will also conduct a duplicate content analysis. If they don't mention it, ask about it.

2. Ask the SEO to give you a list of keyphrases they intend to target complete with associated search volumes. This should be subject to your approval.
- are the keyphrases relevant to your business area?
- do they experience a significant monthly search volume?

3. Any company that says they can guarantee you a #1 position in Google should be avoided. They are either black hat SEOs using dubious tactics, optimising for keyphrases that experience no competition and will, therefore, bring no traffic, or just telling you what you want to hear in order to get your money.

4. Always ask to see examples of ranking successes the company have achieved. If a company says they can't disclose their clients find another company. There are plenty or SEOs who will be more than happy to show off the results they have achieved.

5. Be prepared to have to make changes to your website. In order to give your website the best possible chance of ranking success you may have to make some amendments. The more complete your on-page optimisation is, the greater chance you have of achieving search engine prominence.

6. It is imperative that you trust the consultant/company you are working with. Good communication, clear explanations and hand holding are the least you should expect for your money.

7. Keep your expectations realistic - SEO takes time to achieve results. For a brand new domain you could be looking at anywhere between 4-6 months before you see any decent results. For an established domain it could be less but search engine prominence does not happen over night.

8. You get what you pay for. This isn't to say that all SEOs at the lower end are naff but SEOs usually charge like solicitors ie. they have a daily rate and you buy their time. If their daily rate is £250 and you commission a day per month you will see results slower than if you commission £750 per month.

9. If a company cold calls you trying to sell you their SEO services then they are probably best avoided. Referrals are an excellent method of finding someone reputable, trust worthy and proven. The majority of cold calling companies don't get any hence the reason they're cold calling.

10. If you find an SEO company/consultant you think you'd like to work with, ask to speak to some of their existing clients for a reference.

11. Ask to sign an initial 4 month contract with a commitment to extending it to a 12 month agreement if you are happy. Some SEOs will work in this way, other won't - there's no harm in asking though.

12. You are well within your right to ask for a progress report/update every month. Even if it's just a ranking report and an inbound link tally, it will show you that the work you are paying for is being done.

13. When you find a good SEO recommend them to all of your friends. Let's try and keep these cowboys from screwing anyone else.