How do I know if a seo company is real or a scam?

[Luke]

I don't know why I just don't trust them

Would you use an seo company or would you use Adwords... What's most cost effective ?

[Jim S]

That depends on the product that you're selling. As you already know, Adwords puts your link on the right side of the page when the keywords match. If you're in a saturated market niche, you really have to compete (pay more money to Google than the other guys) to get your link displayed.

The first thing that I would do is consider how many people that you know actually click those ads/links on the right when they see the SERP for your keyword. If you think that the ratio is high, Adwords is for you.

Otherwise, SEO techniques CAN be very helpful, as they will interpret the Webmaster tools display and might be able to adjust the keywords in order to move your site closer to the first SERP. While Adwords does not make any performance guarantees, you ARE able to make the SEO company contract to some specific metric, like "My links get to page 2 SERP by 6 weeks time, and stay there for 2 weeks minimum". You pay with PayPal (only!) and request a refund within PayPal's 45 day refund window if the SEO company fails the performance metric. The SEO place knows that you can/will pay, and you know that you can get your money back if it IS a scam.

It's all a scam... but probably better than what you can do yourself if you're asking this question.

[Shivani]

You can search from Google about its complain.

[Alex]

You can check them by simple way. you need to type SEO agency In the UK.
whatever site come top in search engine you can go for it.