Stage 3: Running it
Update, update, update,…. And then update.
Keeping a page and a shop up to date is crucial. Apart from the fact that search engines love up-to-date pages and pages with (growing) content, it also builds trust for your customers.
A page that has not been updated in weeks or even months will make your potential customers think twice about ordering. Who knows, if the goods you offer are still in stock? Who knows, if you even check and process your orders, if nobody has heard from you in months…
A "what's new" section on the page might be a good idea, however:
Extremes are never good. Don't annoy your visitors with daily updates and page-news either. Daily updates are a rather time-consuming effort. Yes: in the beginning, when you open your page, you will be tempted to post many updates, but trust me: it gets old soon, and you'll realize just HOW much time you spend on that.
It simply does not look good if you start with loads of updates and page-news, and then the frequency decreases all of a sudden. It means for the visitor: Somebody is loosing interest. The page is going downhill.
Pace yourself in the beginning. Updates once or twice a week are OK, but keep this speed up.
When you publish "page news", make an archive of old articles accessible as well. Again this will build trust, since people can see that you have been around for x-amount of time and that you DID take care of the page. A nice side effect is, that you will also have a good track record of how your page developed for yourself.