We run a website to provide cashback for forex traders from all over the world. Now, we'd like to add new services to our portfolio, such as cashback for poker, binary options and lots of online services.Let me explain the current situation for you.We have great position in Google, our average position is 2.4. This is a huge factor for us.Our domain is _forex_cashbackcloud.com. So our domain is really specific for the forex field.We have separate 10-15 emails for every domain (counting aliases). We pay for Google Apps to manage them.We have a special loyalty program, where the more you use our service (which usually means you trade more), the more we pay you back.We have a referral program where users can refer their friends to our site for money.We are on Symfony 2.3, using Doctrine ORM.Our site is translated to 3 languages right now and we're adding 2 more in the near future.Our server environment runs Nginx.The problemRight now, we are facing a difficult decision. Should we open a completely new site and make everything there, under one roof. Or, should we open new sites for every field we'd like to be able to give cashback. Here are my concerns.As we are opening for other fields, like online casinos our domain can't be the one we use now, because it's too specific. However we really don't want to lose our SEO ranking for the current field.We don't want to make users have to log in for separate sites. We'd like a single gate, where they can reach their profileWe don't want to copy and past our code base. If we do it once, it could be working. However, for the third and forth time it could get messy and hard to maintain.Our users have one account right now. They collect their 'virtual cash' on their balance until they reach our withdraw limit and they can withdraw their money. People who trades on forex may use our services on other fields like online casinos. So, they want to collect their money on one single account.Administration and support. If we lots of domains we should have separate email addresses for these sites. That could be real pain in the *ss.To make the matter worse, our current users have to get access to our new sites and of course our new users have to access any other fields too. So, we kinda need a shared database for it. Plus, users must be able to log in to their profile with single-sign-on, we cannot ask them to log in separately for every site.We need to consider SEO in every decision we make. It's a huge factor for us, so we cannot leave it out of the equation.We have lots of pages which will be the same on every site. Obviously, we don't want to manage these pages separately. (Lots of them are static pages like terms of service, privacy policies, about pages and so on) Plus, it could count as duplicated content in a Google bot's eyes and we could easily get punished for that.We'd like our referral to work with any sites, on any fields. For example, a poker player can refer a forex trader and vice versa.We run Symfony 2.3, which works great for us, and we don't wanna change it.I was thinking of a good example here, and I found out Envato does kinda the same. They have lots of domains (www.themeforest.net , www.codecanyon.net , etc.). They have a single sign on and single userbase. However, they have separate balance, and referral programs. But they manage domains extraordinarily well and they change them flawlessly as I navigate on the site.Another good example is Stack Exchange with Stackoverflow. :) It possibly has the same code base for every site, it does kinda the same for every field and it runs on multiple domains, and/or subdomains of Stack Exchange.All in all, my question is that is there a best practice in this? Or some good examples which you can share with me? Or does anyone has experience with these kind of problem. I'd really appreciate the help and thank you very much for it in advance.The possibilities are the following:one completely new domain (we may lose all seo ranking, easier to maintain, low seo synergy, have one codebase)multiple domains with one distributing site like Envato (get to keep our seo rankings, harder to maintain?, lots of emails, duplicated content possibility, higher costs) one domain and multiple subdomains (kinda the same as multiple domains I think. I don't know too much about seo and maintainability in the case.)I know that there is no silver bullet in the case, but I'd be really interested in your opinions. Also, I'd be thrilled if you can toss me some examples how to execute these kind of things in Symfony2.Cheers.ps.: This question was firstly asked on StackOverflow. They sent me here, they said I'll be in good hands here. :)UPDATE 1.0Hi guys, a quick update on the solution here. Right now we're in the middle of a big transition to the new site. We have made a lots of difficult decisions to get here. All in all, we went with the multiple domains approach because we didn't want to lose any SEO traffic.But what about maintainability? I think we figured out something to solve this. We created a CommonBundle in Symfony 2.3 where we store all of our main, common functionality. It's a separate bundle with a separate namespace, including our User managing Controllers, main Model classes and all the common views which could be used for all the sites.We'll use one database with prefixes. I'm not sure here, that this is the best solution, but it's obviously the easiest option for now.To create the actual multisite in Symfony, we used a solution from here. It seems to be working, but I'll get back to you when we know more.
Multiple domains or one new domain or sub domains. Pros and cons
seo;domains;subdomain;domain registration;domain registrar