Microsoft actually seems to specialize in that sort of thing (selling a software product, and then offering some quite expensive, bespoke enterprise consulting services for it). But they are not the only ones, looks around the industry and you'll see it everywhere.
The only real drawback to this model when you're small is that it dilutes your focus and multiplies complexity and cost because you have to manage multiple very different lines of business simultaneously. But if you can overcome those challenges it can make a lot of sense, be an expert at a particular problem, sell a product for the average Joes who have that problem, do bespoke consulting services for the money-laden enterprises who have their own complex versions of it.
But to be fair, basically all enterprise deals involve services as you generally need to train people in how your thing works if you want to get enough adoption for when Finance come looking for operational efficiencies.
Do you know of any examples of small scrappy places that have figured this out? Is there any good writing on what kind of organisational and engineering approaches are necessary to make this step?