>Hi, Craig...
>
><< If your client wants you to slip-stream a new feature, have them pay for its development. This would be an additional cost over any maintenance and/or upgrade fees. If they can't or don't want to pay, then they will have to wait until you get the next release out the door. >>
>
>Interesting idea...
>
>Our situation is somewhat unusual in that each corporate client purchases a corporate license to our product. Once they purchase the license, they get upgrades for free. But the billing idea if they really want something in between updates is a very interesting idea. Because 'slip-streaming' is really against our internal interests, we could set the billing such to discourage requests between quarterly updates.
>
>Thanks,
>Kevin

Kevin,

I would price these slip-stream enhancements very, very high. Quarterly releases are really pretty frequent to begin with. Sticking things in for a particular client can become a management nightmare. In theory you should do full regression testing every time you do this. That might not be completely necessary fo a small enhancement for a single client, but (as I'm sure you know) each time you change the code you open a whole can of worms. Your support people need to know exactly what each client has so they can tell whether a problem could be related to a particular client's version. I have clients who sell commercial packages and we will rarely do anything other than fix a "showstopper" bug between releases.

Your situation doesn't sound that unusual. A lot of vertical apps include free upgrades as long as you pay the annual support fee. Providing free enhancements between releases sounds pretty unusual.