working on for the last five years in the largest integration and asset acquisition that we've done outside of the two smaller ones here in the prior two years, was really effectively finished around the 2001-2002 timeframe.
We've been in effect operationalizing the 11,000 towers for quite a while and have systems in place that scale very efficiently from the standpoint of our IT systems, the processes that we have our organization structure. This business does in fact scale, and that's one of the things that I think we're all aware o , and I think from Global Signal's perspective, and certainly I'll let Jerry speak for himself in that particular regard, that was one of the things that I think was intriguing from Global Signal's perspective which was the ability to accelerate the potential of their tower footprint by merging it into a company that had already established all of the system processes and so forth.
Rick, I'll add a little bit to what John said, although John said it very well. We are and continue to work very hard at improving the systems process and procedures we've got around here, all with the objective of delivering better customer service and we are making a lot of progress. I'm very happy with what we've accomplished. To date our folks have done a terrific job and are dedicated to doing that. That being said, it's still got a ways to go and requires a lot of time, effort and money.
As we've spent time together with John and his team, as he said, one of the things that was particularly exciting to me was to be able to take really a quantum leap in operationalizing Global Signal. They went through at Crown Castle I think a very similar process to what we're going through except that they did it three, four, five years ago so they've got everything already in place today. They've had all the learning, the painful lessons. That's all behind them.
We're in the early stages of that so I think when we take our real estate assets, our portfolio, apply the Crown Castle systems, processes and procedures on top of that, there'll be a dramatic, as John said, acceleration in our ability to not only deliver great service, but ultimately drive the free cash flow growth that this transaction really is all about.
And then, Ben, I think you said it when you talked about this transaction enhances the ability to achieve the 20% to 25% growth rates. Does that mean you guys weren't comfortable with your base portfolio and does "enhances" just mean it gets you comfortable that you can achieve it or does "enhances" mean we should be looking at a higher number than 20% to 25%?
I thought you might ask that question, Rick. We debated that one. No, enhancing meaning it's just mathematics. Our view being that you're acquiring a portfolio that has 65% of the tower gross margin run rate per tower. Given our leasing prospects that we see across the Global Signal portfolio, back to the comments I made before, it's just simple math. We see
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