Start with the commercial constraint
If you need to test demand for a defined service, paid search can provide feedback once tracking and campaigns are ready. If your business has an established offer and a long-term need to be discovered, organic search may deserve sustained investment. Neither channel compensates for an unclear offer.
Check what happens after the click
Review the destination page before increasing traffic. Can someone understand the service, establish whether it fits their needs and enquire easily on a phone? A focused improvement to the page may make both channels more useful.
Compare the full cost
For advertising, separate media spend from management and landing-page work. For SEO, allow for technical implementation and content production as well as planning. Compare the resources required with the value of a suitable customer, rather than comparing a monthly fee in isolation.
Use one shared definition of a lead
A form submission is not necessarily a sales opportunity. Agree what makes an enquiry relevant and feed that assessment back into campaign and content decisions. Avoid judging a channel solely by its traffic volume.
Make the first decision reversible
Set a starting scope, a review point and a small number of meaningful measures. You may start with one channel and add the other as the evidence improves. A joined-up plan lets search insights inform ad messaging and paid-search learning inform content priorities.