How do you Choose a Reliable and affordable SEO Company?

There are lots of SEO Companies operating which would provide your required services.To choose best among them.I would suggest you a strategy, First, ask the company about their portfolio's, after analyzing their portfoliOS and projects decide Do you really satisfied with their work. If you then only choose that company, otherwise switch to another, there are lots of companies. This tactic is used by me when I need marketing services for my company.Within few weeks, my website traffic and sales increased.