Hi,
I know the title of this thread is quite bad, but dont know how to explain it in one sentence

Okay, I got a shop running and did much OnPage-SEO and Linkbuilding (only white hat of course), but the problem seems to be that there is not enough content. Now I think about creating a blog to put some content on.

Question is if it is better to put this blog on a new domain (also another ip) and then link to the shop as often as possible or to put it on the shops domain?

Thanks and sorry for bad english

Put it on the shops domain.

If you link to the shop from another domain, it´s just a simple backling.
You can get Backlinks with strong PR from other sources.

PS: If you link to much to the same site from one IP, BigG may hurt you for spamming