I'm not a patent attorney, but I do play one from time to time -- I've had a software patent application pending for over five years now. Of course, this is not legal advice, etc., etc. I assume you have a real patent attorney somewhere in this picture.

The flip answer is "hope they do infringe and are wildly successful and then sue them for all of their profits when you get your patent." The protection is retroactive to your date of application. Generally, the application is published after 18 months, so there's not much you can do in any event to keep your technology under wraps.

Some companies actually used to sort of encourage infringement in the pending period, following more or less the strategy I described above. My company got nailed for infringing the Unisys LZW compression patent. At the time we implemented the algorithm, Unisys was encouraging or at least tolerating magazine articles about how to do so, with no clue that they had a patent pending. This sort of strategy was called a "stealth patent," and the PTO put the 18-month-publication procedure in effect specifically to derail this strategy. Unisys said "hey, we're nice guys, we're not going after BACK royalties, so you got a 3-year royalty-free license to use our patented technology." That was no help to us because we had a product that would have been very difficult to re-engineer for reasons that are way beyond this digression.

More seriously, you probably don't want to encourage infringement. Unless you have a legal department the size of Unisys's, it may be hard to collect your royalties, so the above might not be a great strategy. I think you have to follow Mark's advice. Pretend there is no patent application. Heck, it might never issue. Be the best software company you can be. And if competitors infringe, and your patent is issued, well, then maybe you have some gravy coming in the form of back-royalties.

I'm not a patent agent or a patent attorney. However, I have helped people file patent applications in a number of fields and personally have a software patent application pending. The recommendations that I've heard from the experts is pretty similar to what the other people who have posted here have said.

I would rely on commercial success not patents for success with a software product. Software and business methods patents take very long to get (much longer than most other art groups at the USPTO). You don't know if your patent will be granted, and if so what claims will be allowed. It also appears to be easier to "break" a software patent after it has been issued by finding other prior art because there is so much prior art.