4:user decides on the limit of ads he decides to view [X perday/perweek] and also the time when he wants to view them.

5:when the user doesnt accept ads> the user is reminded, at every software update for the program, that he has chosen a program where the dev has requested contributions for continued support of the program, and it would help the developer sustain the product.

6:using something similar to popularity contest, note the number of users using the software and pay the dev according to popularity of software and ads generated.

7:the revenue generated for the project is displayed on site[example:ubuntu.ad.repos.com], where revenue for the month/year/total is shown...along with the amount the dev requires to maintain the project... so when the users feel that enough revenue is being generated they can opt-out of the ads.

8:canonical pays from this revenue, the extra employees needed to maintain this repo and its quality control.

this may seem far fetched to allow ads in linux , but unless the small devs get paid ,quality products wont be unlimited.

take google for example: its free, we all enjoy it free but it gets paid by ads and the devs get paid pretty well.we also have the option of using customize google extension where we can block ads.

this is almost like apple app store but FREE for the users.

the most important thing is that since
1> the dev sets the amount required to support his project ,
2> the repo controllers agree that the requirement is not too huge
3> as the users accumulate for that project ,the users might not even need to view more than a single ad a month for maintaining the project. if its in the millions of users for the project maybe one ad a year. that is definitely not a burden for anyone!

BOTTOM LINE IS DEVELOPERS NEED TO BE COMPENSATED FOR THE LOVELY PROGRAMS THEY CREATE.AND TO KEEP CREATING MORE PROGRAMS.

I can already see many problems with the above (what happens if you're using an older apt client that doesn't respect financial meta-information; the package gets downloaded for free). There are almost certainly more elegant ways to solve this problem that will be apparent to other Debian and Ubuntu developers, and I encourage you to elaborate on how this might work from a technical standpoint.

It is also important to note that while Apple's app store primarily hosts non-free software (free as in beer, and free as in speech), and uses DRM to ensure that users do not make copies of this software, I believe that neither of these features are essential to the success of an Ubuntu App Store. It is possible to imagine individual users swapping .deb's of contribution-based software via filesharing networks, or visiting the authors' websites to compile "contribution-based" software from source and package it by hand; and, according to the terms of the GPL, and most other free software licenses, they would be completely within their rights to do so. However, such methods are much less convenient than simply clicking through a graphical interface, and obtaining your packages directly from Canonical, especially with respect to the demographic of non-technical users that Canonical would like to target. Just so long as value is added to the software in some way, be it by way of convenience or by some other means, then a "contribution-based" repository will be used over other methods of obtaining and installing the software. Additionally, I feel that many Ubuntu users would like to see developers get paid, and thus would be more inclined to use such a service.

In conclusion, while putting a price on software that has otherwise been free-as-in-cost might at first seem a bit unusual, we must consider that providing a convenient, direct mechanism for developers to be paid for their software will help, not harm, the Ubuntu GNU/Linux distribution, the ecosystem of free-as-in-speech software, and the Free Software Movement in general. It will attract more users and more developers to the Ubuntu GNU/Linux platform, especially as such a mechanism does not exist on Microsoft Windows. One need only look to the success of the Apple App Store, and Sun's soon-to-be-launched Java app store, to see that there is a demand for such a distribution model.