How to properly implement a site with pages for each city in the country?

Question

Google

Hello!
I plan to make 1 site but with pages for each city, since now I have a lot of sites for each city.
Why ?
I am making a CRM system and I would like to automate everything, unify it, but it will be very difficult with different sites.
I planned to buy a domain for each region, but after reading a little Google I realized that it would be expensive, since the main site would not have "masses".
Each city has a branch, and for each branch there are 2 sites (two types of services are different).
Tell me how to implement ONE site but with the right optimization of pages for cities?
Indeed, in Google, you can advertise a page in the city under which the page was made.
And I also thought about ip to calculate the user and open the page of the city in which he is now localized.

Answer 1

1. If you do the calculation by the user's IP, this is convenient, but in this case it will be necessary to add search engine robots to the exceptions so that only one page is not shown to them when they enter (Yandex has Moscow IPs).
2. If you make one site for all cities, you need a clear structuring of sections. In the head without improvised means, it is impossible to reproduce everything that is necessary. But based on the description:
- each city should be a section. Inside the section there are pages with two services
- the contact page needs links to all city pages
- depending on the number of cities, the service pages should be relinked. those. inside the services you need links to neighboring cities from the same region
- each city should preferably have its own number, address, opening hours, photos of staff.
3. Subdomains remain the best, cheapest, and fastest way to promote sub-regions. But I don't know about the complexity of developing a CRM for subdomains, because in fact they are different domains. But if subdomains do not become a problem for the CRM, then this is the best development option. With them, here is such a scheme
- for each city we make a separate subdomain with services
- on the main site on the contact page we put links to all subdomains, indicating in which cities we provide services
- there are only 2 pages on subdomains with different services, all other information on main domain.
- in the Yandex webmaster, we clearly indicate our region for each subdomain
4. One site
pros:
- "weight" is not smeared, stored and accumulated on one domain name
- convenience for developing a CRM system
- ease of programming if necessary (adding services, changing functionality, etc.)
cons
- search engines will be around for quite a long time determine the relevance of a particular page (3-6 months)
- it is impossible to pinpoint the region in Yandex
- it is difficult to indicate links to organizations' websites on Yandex / Google maps (they can be mistaken for spam, since the domain is the same. Time to find out since then As a result, they may generally forbid linking to one domain in different cities)
5. Subdomains
pluses
- a clear division by city (for ps, a subdomain is a separate site)
- an exact indication of the region in Yandex
- no problems with Yandex / Google maps
- faster determination of relevance and positions on queries (2-3 months)
cons
- possible problems in the development of CRM
- more expensive development relative to one site due to the more complex functionality of the relationship between subdomains and the main domain

Answer 2

I am making a CRM system and I would like to automate everything, unify it, but it will be very difficult with different sites.

Why, there can be many fronts, and the admin part is 1 and 1 base.
I don’t see the point.
Different cities are usually done on a subdomain, unless of course the information there is different, if not different, then the city is just a parameter from which contacts change. There is no unequivocal answer until there is a vision of the entire project.
maybe it makes sense to make 2 sites for each service, if they do not intersect