question regarding blogspot seo.

i have a blogger blog

is buying a domain name for it changing anything for seo?

i have the ability to map a custom domain name for it.

upzzz

I would say yes, Google will look at your purchased URL and try to rank your blog based partially on the purchased URL and If the domain you are purchasing has your keywords in it, the backlinks you build to the purchased URL. The purchased URL should be better for ranking purposes as long as it contains your keywords. A purchased url with your keywords is much better than the ultra long URL you get from blogger.

will help definetly

If you're gonna purchase a URL...I'd say go all out and get a wordpress blog. It's so much better for SEO than Blogger is. There's only so much that you can tweak for SEO purposes with Blogspot. You can also convert your already existing blogspot posts and import them into a wordpress database. Easy as pie...better for SEO all around.