Your business concept having similar products and/or services is a good sign. This means that there is a market demand for whatever problem you are addressing. Go a little deeper, and if you look into patented "business processes" (or software patents), I'm sure you will most likely find your concept protected some way or another. But all of this is irrelevant to your question of feasibility in pursuing this as a new business.
The feasibility of success revolves around your team's capability to out-execute and disrupt the current market. Also consider this: capturing a small portion of a large market is much greater than capturing an entire portion of a small market.
I can think of many many examples, but I'll use Wufoo as an example. Wufoo is a service that simply made custom forms easily embeddable to web pages. Before Wufoo, there were many many other FREE services that did essentially the same thing. They disrupted the market by introducing ease-of-use and a user-friendly focus. And then ultimately exited (got acquired) by SurveyMonkey for a whopping 2 digit million exit.