I have seen many adverts from seo companies that they guarantee the top10 for keywords or pay money back. What is a trick. Because 1. They even do not ask for keywords promissing such thing 2. Google is Google and no one knows what will be tomorrow 3. They pay money back?
It's a way for SEO companies to get business from naive webmasters. You wont find a reputable SEO on the planet that will guarantee top 10 position like this - as you said, they'd first take your keyword and give you estimates based on that. Best rule to follow: if they guarantee your position before you've spoken to them, find someone else
I start this topic because my clients say me " We know a company which promiss us a top 10 in Google or money back" I always answer " Yes, if your keyword is " winter Olympic games in Gobby desert "I can give my word as well", but how they explain customer that they do not achieve top 10 and do they pay money back?
You need to assure them that you are genuine. Show them your portfolio (if past clients allow it), talk them through the benefits they can expect from your service and, which works best for me, take some time to talk to them about their business strategy and how SEO can be integrated into it. Give a bit of time, go the extra mile and it truly pays off.