Should I buy PPC ads if I rank organically?

You have optimized your website, and now it ranks in the top ten for all your major keywords and first for several. Of course, the web site rank first for the brand name (and if it doesn’t, then you really need to examine your online marketing strategy!)

The question at this point is: should you pack in the pay-per-click (PPC) adverts?

In my modest opinion, it might not be the best move, and continue investing money on that it means to ditch them just because the onsite optimization worked. But maybe I’m wrong, and so I would like to know what do you think about the following.

Today, while I was working  for a customer, I noticed that despite their brand name rank first they are still investing in PPC adverts.

Let’s say this customer has a version and .com version for the two different markets, but substantially the two web sites are pretty similar in terms of graphic.
The audience is different of course, as you can imagine the version targets Brits.

But why continue to invest money of PPC?

When I asked this to the PPC account manager, I’ve been told that in case like this, Brits (or whoever in case of other domain) prefers to click on the localized TLD.

Adidas PPC

I don’t think this is true, especially considering the first organic result was better styled thanks to the sitelinks, giving to the result a nice portion of the screen. Ok, the PPC was immediately on the top, because the bid rate most probably has been configured at the maximum level, but does really a standard user looks at the domain extension?
I’m not talking about a professional or a marketer that maybe they know the difference. I’m talking about the general audience.

The images is just an example (I cannot disclose the customer’s name), but imagine the same layout: a ppc (without Ad sitelink) pointing to the UK version and the organic result with sitelinks pointing to the .com version.

In a condition like the one show below, where are you encouraged to click?

For the reason I’ve been given, investing in PPC in case like this, it is not a good investment. If I ¬†would have been told “we need to occupy more space”, probably I would have agreed. But I’m sure that a good optimization of SEO factors like geographic target in the GWT, rather than an internal redirect after a user-agent sniff, certainly could be more cost effective for the specific case.