A few thoughts...
Hello! I actually just launched an online store and one of the concerns I had was how to keep new and relevant content flowing through the site to attract attention from the search spiders. A couple things I've done already or will be implementing soon are:
I added a Reviews page to the online store where I will do regular reviews of featured products;
I created a YouTube channel where I will post video reviews and have a video player on my front page that links to our channel and the latest review;
I created a separate blog that has reviews and information about office furniture, manufacturers, consumer news, etc. From this site I link to the store. I do this as just another way to drive links to the store plus it gives me an unbiased platform to report from.
Of course the basic on-page factors...domain name, title, description, and keywords. I put most of my efforts into the page title and a clear and detailed description as I understand the dwindling importance of keywords in the meta tags (I do strive to have keyword rich content however!)
To build our mailing list, I created a contest where a visitor to the online store can win a free chair by entering their name and email. I am also going to develop a creative for the blog that links to the online store.
I am going to create a QR code for the online store that will automatically issue a 5% discount for joining the mailing list also.
I have set up a Facebook page that automatically posts to our Twitter account and we are ready to begin running daily specials there.
I am penning articles for submission to the various ezines and article directories.
And certainly not last or least is participating in forums and commenting on blogs.
Whew! Now that I look at it, it's no wonder I'm beat at the end of the day!
Well, hope that was of some value to you...and I hope the marketing agencies don't hate me for giving away their secrets.