is the ranking agorithm for froogle similar to google? do you think the more often you submit a feed, the higher you will rank?
What's the point in keep submitting a feed. You will only submit a feed again if it changes. If you keep on submitting the same feed then it will just annoy Google as they have to manually approve each one so that they can make sure all the data in the datafeeds are correct. Submitting your site time and time again to Google doesn't give you better results, it just wastes your time.
Google says you should upload your feed frequently. Back to the original question though, I doubt frequency of updating has anything to do with ranking.
The reason why they do that is to stop people uploading a datafeed and then forgetting about it. If they done this then their product links will become broken the product prices will be different to the froogle results prices, etc.
its a good rule of thumb other wise people just upload and forget. this way you wil monitor and only up to date info will be listed.