As a conversion rate optimisation agency, we're always going to say yes to this question, but there's a very good reason for it.
Some of our clients are laying down hundreds of thousands of dollars in ad spend each month. With some thoughtful changes, they can see significant increases to the ROI on their spend, with a fraction of the investment.
However, for stores that aren't quite at this level, we usually recommend doing a one-time project to clean up your landing pages in order to maximise the effectiveness of your other marketing efforts.