Big difference between business and personal adsense accounts

[jukka79]

I have noticed a huge difference between Business and Personal Adsense accounts.
Moving one site from Personal to Business account, decreased CPC permanently about 25%. I have quite a lot of data (1 year) and the drop is quite clear and seems to be permanent.

Could the reason be that between businesses, Google needs to pay VAT (Ireland). So for Google it costs more when the publishers site is under business Adsense account and the publishers VAT registered company is inside EU. (If publisher is outside EU, it's a different case) And when the site is under personal account, no VAT numbers provided = nobody pays VAT (atleast Google).

So is there a "VAT penalty hit" in CPC ...or is this just something else. Has anyone seen similar?

[anarki]

don't think so. business to business has no vat cost. yes, they pay you now with vat, but they can claim them back.

[matbennett]

VAT is removed at source and accounted for by reverse billing. This means that is doesn't effect publisher earnings either way (if you are VAT registered you would see the same being reported as if you were not).

Moving from one account to another often brings a performance drop. Check how much placement targeting you had before the move. That would be lost for starters.