Remember my article How to earn money with your application through the Android Market? There are some greedy persons out there who might want to take advantage of the “free software” delivery of the Android Market. I will tell you below what is not allowed and why.
What you should not do
The article mentioned above described how you can get up a demo application on the Android Market. It is obvious that this provides possibilities to add a purchase link into the demo application so users can buy the product on your own site. Good idea in the first second, but be aware of the Developer Distribution Agreement you agreed to.
To be clear: This is not allowed.
You will create more of a mess than if you do not have your application available in the Android Market. Sooner or later your application will be reported by a user or another developer (god bless the community!) because you are violating the distribution terms other developers comply with. Don’t blame them – it is just unfair that you are violating terms while they are complying with them. Once your application has been reported to Google it will investigated. I don’t know exactly what happens then but I guess a nifty Google nerd will install your app on his phone and check it out. They will see that you are linking to your own shop and kick you out of the market. This does not help you in earning money out of your application. May be in the very short term while people are actually buying from you. However, in the long term you will not be able to establish a successful relationship with your users which will lead in less popularity and less sales in the end.
Want to do it right? Check out: How to earn money with your application through the Android Market