SEO best practice for page that is the same for 50 US States

I have a calculator for each US state: for example let’s say you plug in your income and it tells you your state tax rate, which depends on your state.

The calculator has the same UI for ever state, one simple form. The only difference is the page title and H1 tag "PA Tax Calculator" and "Pennsylvania Tax Rates." Of course, your results depend on the state which is generated using JS.

I am trying to decide between:

  • 50 Unique URLs that I send to Google: example.com/calc/?state=PA and example.com/calc/?state=CA, then state-specific titles on Google: "PA Tax Calculator"
  • One URL for indexing (example.com/calc/) that then uses a select form or geolocation to select the correct state. Leave the Google page title generic: "50 State Tax Calculator"

I’d like to be able to put the state title in the Google search title as I think it would feel more personal for vistors, but it seems like if the 50 pages are too similar it’ll just be diluting to have 50 identical pages. This is my first time trying to figure out how to get visitors via SEO.

The best practice of Article / Web 2.0 / Blog submission in off-page SEO?

I am planning for my e-commerce new project. And I am stuck at the best practices of off-page submission for Articles / Web 2.0 / Blogs. I have some questions in my mind which are as follows:

  1. Can I submit the same Article / Post (or content) in different off-page submission sites?
  2. How can I measure that which off-page submission sites are important or useful (like any terms DA, PA or DR).
  3. And How much content submission will effect my domain progress or good link equity?

Is it poor practice to host multiple web applications on the same domain, in terms of cookies?

In my web application, I have a single API backend and two frontends written as single page applications. To simplify deployment, I’d like to serve the API on /api, the admin dashboard on /admin, and the end user frontend on /user (or something similar), all on the same domain.

I want to use cookies for handling sessions, for both the end-user and admin apps. Is this a good idea? As I understand it, cookie usage is restricted by their domain. Would it make it simpler for an attacker to steal admin-session cookies from someone logged into both frontends? Or, should I use different domains for the admin and user frontends (admin.mydomain.com and user.mydomain.com)?

Halting problem theory vs. practice

It is often asserted that the halting problem is undecidable. And proving it is indeed trivial.

But that only applies to an arbitrary program.

Has there been any study regarding classes of programs humans usually make?

It can sometimes be easy to analyze a program and enumerate all of its degrees of freedom and conclude that it will halt.

For example, has there ever been an effort to create a programming language (scripting really) that guarantees halting? It would not be widely applicable but could still be useful for mission critical modules.

Best practice in IIS of redirect (wildcard) from one domain to another?

We are moving domains and servers. I have newdomain.com set up on new server (SSL).

I want to shut off old domain. I will get old domain pointed to new server.

Is it better in IIS to add the olddomain.com bindings on new server under the same IIS Site? Or is it better to create a new IIS site for olddomain.com and redirect it to the newdomain.com from there?

Another dimension in here is we could have links in both http and https but sites both require https. So one of the things I am worried about is redirecting http://olddomain.com/xyz/index.html and that it needs to redirect correctly to https://newdomain.com/xyz/index.html