Post this question to the appriopriate forums and you'll have a lot more sceptics than those who say they are making money from Adsense. As you might have already known, the fundamental principle of Adsense is the filling of space on your webpages with Ads from Google. Of course, the pages need some HTML codes from Google.
If the primary reason for creating your site is e-commerce you will be faced with fierce competition from the Google Ads which are supposedly there to make money for you. You cann't perfectly filter the Ads that Google sends to your site. It would be a good idea to use a non commercial website for the Adsense business. Google can evaluate your website and figure out if it is designed to target particular segment of the population (say gardeners) or not. Google will then selectively send Ads to your site or flood it indiscriminately with Ads. It all depends on the results of its evaluation. A webpage clustered with all sorts of Ads is a failure. Remember that you get paid when the Ads are clicked on not when they are seen. Does your site appear within the first ten pages of the major search engines? For this to happen two conditions have to be met: (1) The right HTML code (2) The proper paid submission to search engines. You can create multiple sites for multiple streams of income. This could be very tedious and perhaps impratical to do manually, even if you are proficient in HTML. Consider using an automated program for this.