How to get long time clients

We are a startup web development venture based in India,we have some one time clients from e-commerce industry but they will not benefit us in the long run.So we are planning to showcase the work we done with this clients and acquire some international clients to grow our business.But we want some information:

1.We dont have any idea how we would reach or contact overseas clients who can provide us with potential work in e commerce platform.

2.We are also thinking about social media marketing but there is also same problem how we are gonna reach those who can provide us the potential work please suggest how to get such long term clients or how to proceed to them.

3.i have heard that there are some international marketing agencies who outsource such works can any one tell us how we can reach them and what things are needed to prepare for that.

Any help will be appreciated.

I'm afraid this is common in web development agencies for small clients, delivering end to end site/app. Once you delivered the main site to client, his budget and time will favour operation, marketing etc. There will still be budget for maintenance and continuous improving, but not that much as main project. And that budget is only available if the site is successful.

Seeing such a situation, I think you'd better define "long time client" as "satisfied and successful client". "Satisfied" means he will still work with you when having budget, "success" ensures that budget.

Once you have enough such clients, you don't need to worry about new business too much. Every client will have small but easy work for you. The sum will be big.

Before you reaching that point, you'll still need to work hard on gaining new leads and contracts.

Another important consideration is to do your best to help clients' success, rather than simply follow, make and collect.

My two cents.