I see that there are a lot of development agencies from all around the world that try to convince potential clients, mostly through the same pitch, that they provide great services. I am curious about ways to stand out of the crowd and how do the "potential clients" look at these situations.
When you say "tech agencies" are you talking about dev firms? If so, there are 4 things that will move the needle:
Don't compete on price, focus on the other 3. Emphasize the collaborative nature of your working relationships. Offer similar references to them in terms of type of project and company size. Let them know how in each case, you didn't simply follow orders, but found a way to improve each project somewhat. Finally, give them a sense of how you stayed with the project until each of your previous clients felt satisfied.
The thing that makes you unique will be the people and the experience you offer. Also, when you go in to make a pitch, start by finding out what they are looking for in a resource, not just "pitching them". Ask what has been disappointing about previous agency relationships. Ask if this is the first time they are using an agency. If not, ask why they are not going back to the old firm. The more you know about what they like and don't like, the better able you will be to present yourself as a great solution.
Tony, thanks for taking the time to give me such a complete answer, much appreciated.