Paid advertising stops the day you stop paying for it. Search does not. It is slower, it is less exciting, and over a couple of years it is usually the cheapest customer you will ever buy.
Rankings are the output, not the work. These are the inputs, and they have to be done roughly in this order, because there is no sense earning links to a page Google cannot properly crawl.
Crawlability, speed, structure, and the quiet things stopping Google indexing half the site. Unglamorous, and it goes first because everything else depends on it.
Pages that answer the search rather than mention the keyword. One proper page for each thing you actually sell, instead of one page trying to be all of them.
Earning mentions and links from places that already have standing in your world. Slowly, and never bought, because bought links are the fastest way to undo the other three.
Google Business Profile, reviews and the map pack. For most Sussex trades this is where the enquiries actually come from, and it is the layer most often left half finished. If you build for a living, the trade-specific version of this is SEO for builders.
Every agency will run you a crawl and email you a PDF full of red warnings. Below is the sort of thing it turns up on a site that looks perfectly fine from the front. The value is not the list. It is the person working through it.
This is the part agencies are usually vague about. We would rather you knew the shape of it before you commit to anything.
Audit, technical fixes, tracking, and sorting out the pages competing with each other for the same search. You will not see a ranking change. You will see a faster, cleaner site.
The service and location pages that do not exist yet, written properly rather than spun. Movement starts on the longer searches nobody else is bothering to fight over.
Links, mentions, citations and reviews. The competitive searches start to move, and for local businesses the map pack usually shifts before anything else does.
Enquiries arrive from work done months earlier. This is the point where the conversation stops being about rankings and starts being about the business.
Search is the only channel where the work you paid for last year is still working this year. It is also the only one where nothing happens for the first two months. Both are true, and we will say both before you sign anything.
The honest version
Plenty of agencies will sell you a report full of red warnings. The work is doing something about them, month after month, and that is what this is.
SEO is the easiest service in this industry to sell badly, because the results arrive long after the invoice. If it is not right for you we will say so on the first call and point you at paid instead.
We will look at the site as it stands, tell you the three things holding it back, and be straight with you about whether search is worth your money at all.