Measuring the impact of content marketing should not be too complicated for most businesses.

A simple example:

Content marketing costs £10
Which brings in sales of £30

To find out how much you gained, you subtract what you spent from what you earned:

£30 (what you earned) – £10 (what you spent) = £20 profit.

ROI tells you how much profit you made compared to what you spent. To get your ROI, you divide the profit (£20) by the cost (£10) and multiply by 100:

ROI = (£20 / £10) x 100 = 200%

£10 spent led to £20 profit, or for every £1 you spent, you made £2 in profit!

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However, where it becomes complex is that many businesses (especially smaller businesses):

a) Don’t really know how much their content marketing costs
b) Have not specified goals (such as revenue generated or number of leads)
c) Have not / cannot implemented tracking, so do not know when a goal has been completed
d) Are not sure how much an acquisition is worth

These reasons are why, although calculating content marketing ROI should not be complex, it often appears to be so.

See also
Download a content strategy template
How to improve your website content