A customer wants go give me advertisement on my website. He wants to be opened his website with iframe. But that iframe will be 1X1 pixel .So directly all visitors will enter my website but they won't see something The thing that i want to know whether this type of act effects my google ranks?
Its a widely accepted fact that iFrames are disadvantageous to your site. IMHO, you wont receive a ban or something, just that your rankings will deteriorate. Also, why exactly does your customer want an "invisible" advertisement?
They are not good for SEO. so avoid it, you can check the Google Support center pages where you can easily find that Google Never Recommend to Use Frames