The first thing to do is NOT to think what method you need but to start by turning your business objectives into research objectives.
Watch video 2 in the series or Learn how to do that here.
The main options are: to discuss, observe, collaborate, or even by-pass talk completely. There are online options for each of these too. Often projects are ongoing and require the use of quantitative as well as qualitative data, and more than one method within qualitative.
Case study from the Times top 100: How market research enabled Barclays to improve its student account offer
Case study from the Market Research Society showing how the Money Advice service integrated a range of methods to overcome its research challenges: MA Mixed methods case study MRS