Hello SEO guys,
How footer links affect site's ranking in Google? For ex, ther're a lot of links with anchor
text "Powered by" and url to my website.
Oh yes footer link does have affects on your site. Suppose if you are a web designer then footer is used to acknowledge the creator of the page/templates or the person/webmaster(would be you). Sometimes footer links are used to have additional acknowledgment links for site and use as a backlink in return to the free products or services which you would definitely want for your site.