There are plenty of industry-specific reasons why a company will use a 3PL for cross-docking/flowthrough. But generally, if you want to avoid storing products in a warehouse, immediate shipping solutions might be your thing.
Imagine your company’s products are pre-tagged (barcoded) or ready for sale. If you find that your turnover has increased since your original need for warehouse space, do a cost/benefit analysis and reevaluate your logistics plan.
Those warehouse in/out charges adds up. If business is good and you’re pulling your pre-tagged product often, do the smaller quantities justify inventory costs? Reevaluation might indicate potential benefits to immediately shipping shelf-ready products.