It is such a difficult question as the click through rate CTR is relative to so many factors.

Ads shown in search results tend to have a better CTR than ads shown on the content network, but again that can depend alot on what content sites an ad is shown on and where the ad is placed.

I assume that the company is paying for cost per impression (CPM) rather than cost per click, which is why the figure would be important.

My CTRs tend to be between 1-20% but that can vary so much. Sometimes changing ad text or choosing specific sites on the content network to show ads, can improce CTR.

I once got caught out on the content network where some site showed my ad about 10000 times in five minutes which cost me, it was refunded, but I prefer ppc since then.

The only way really to gauge anything with adwords, is on ROI, as a CTR of 1% could show a better return on investment than a CTR of 50% or vice versa.
So it is hard to say what an average should be for any given product, if an ad you have is receiving more impressions than you think are reasonable and that you pay for, as happened to me, then contact Google and ask them to check, as if you are paying per impression, there is the possibility some site can record impressions that might not be actual visitors, although I am not sure why they would do that, as they are paid per click.

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