I am glad that Europe has once again rejected software patents by voting 648 against and 14 for the ruling of the patent - software directive.
I hear that arguments have been made that software patents are helpful for innovation and that venture businesses may in some way benefit from software patents. I can of course imagine cases where software patents might be helpful for startup companies, but from my personal experience, they are generally more of a burden on innovation at the venture level than a benefit.
Generally speaking, filing for patents is an expensive and time consuming task. Most startup CEOs don't understand and can't afford a patent strategy. I have done a number of calculations on the cost of filing and maintaining software patents, and one estimate we did for a company that I am working on was that it would cost about $750,000 to file and maintain a single patent in the major markets over the lifetime of the patent. Most companies I invest in raise only $1M or less their first round. In addition, to properly protect a technology and continuing developments around a technology, a portfolio of patents must be filed or you can be "surrounded" by application patents and derivatives filed by competitors. In away, filing a patent is practically like putting up an ad balloon for people to see where you are focusing.
Some startup companies I have looked at and worked with have in fact, invested in a portfolio of patents, but from my experience, most of these companies end up spending so much time on their patents that often the products never make it to market. The patents just become fodder for some large company when they are purchased in the bankruptcy fire-sale.
For companies who are working in a patent riddled space, I definitely do a mental calculation of the added risk of litigation and subtract that value from the valuation of the company or decide to not invest at all. I've heard to software patents referred to as land-mines in this context. The problem is, big companies gobble up patent portfolios from bankrupt startups and then have teams of lawyers who use these to go after competition. There is a measurable chilling effect. (Note also that some of the technology oriented anti-file-sharing bills that have been proposed will have a similar effect.)
The only practical use of software patents that I have seen are defensive. Many Internet companies that I have worked with have one or a few broad software patents that they wield to threaten potential assailants. Typically, these company spend very little or no time trying to extract license fees from competitors, but just use the patent like some sort of legal scarecrow. Patents are supposed to be an incentive to innovate and this defensive use really is just a cost and does not serve to cause innovation.
I personally believe that software patents are primarily the tool of large companies with portfolios of patents which they cross-license with each other. Generally, it serve to keep competition out of the market and allows those with patents to push those without patents around or cut them out of markets entirely. A number of open source licenses are now dealing with software patent issues by creating incentives for participants not to litigate against each other. A focus on open standards is also another important way to try to keep innovation unencumbered by patents.
I am not against patents generally and I have worked in materials science and manufacturing technology companies where patents serve as a strong incentive for innovation and royalties provide a fair return for the investments. I just believe that the notion that software patents somehow help venture businesses is a red herring and that software patents are primarily a tool for software monopolies to stay keep the little guys out.
I am basing my opinion on personal experience. Your mileage may vary. I would be interested in the opinion of any VCs who feel strongly that software patents generally increase innovation and investment in venture businesses.