There are several firms and companies who claim to improve your Google page ranking over night. They claim to have your page on the first page within days and will submit your pages to a thousand search engines.
Well, first things, first.
1) There aren't 1000 search engines.
2) Watch where they put your page -- on search results or on advertisement columns
3) You should show the same skepticism that you show to "burn fat over night" pills.
4) There is no such thing as priority submission on Google. The only way to submit is "SubmitURL" feature.
When an SEO firm approaches you, these are the questions you might want to ask:
- Can you show me examples of your previous work and share some success stories?
- Do you follow the Google Webmaster Guidelines?
- Do you offer any online marketing services or advice to complement your organic search business?
- What kind of results do you expect to see, and in what timeframe? How do you measure your success?
- What's your experience in my industry?
- What's your experience in my country/city?
- What's your experience developing international sites?
- What are your most important SEO techniques?
- How long have you been in business?
- How can I expect to communicate with you? Will you share with me all the changes you make to my site, and provide detailed information about your recommendations and the reasoning behind them?
(Adapted from Google WebMaster guidelines)