I work for an online cycle shop who keep all our discontinued product pages online, so that people can see the stats of their old bike, if they ever needed to go back view it again. This causes a problem on search engines because the web pages of the older ‘discontinued’ version of products generally ranks higher than the web pages of the newer versions of the same product, which we have in stock and want to sell. For instance, lets say someone searches for “Kona Coilerâ€, our old “Kona Colier 2006†page appears on third on Google organic listing, when we really want the “Kona Coiler 2008†page to appear in its place. We have tried adding the web pages of the discontinued products to the robot.txt file, but the web pages of the newer version of the products haven’t reached the same high ranking positions of its predecessors. We have thought about redirect users clicking on the old pages to the new page of the product, however, this might confuse people. Does anyone have any suggestions on how we can overcome this problem?
The best solution with this in Ecommerce is to mention it's out of stock, then link to several of the most related products. This preserves links pointing to the out of stock URL's, and helps pass authority throughout the rest of your products which are in stock with good anchor text. Also when Google crawls, instead of hitting a brick wall it has URL's to continue indexing. The best thing, you may even make a sale by providing other relevant products the user may be interested in and if the item comes in stock again you have an indexed and ranking page just waiting for it.
I agree with sweetfunny 100%, most likely if someone is clicking through a search result for a specific product it wouldn't be hard to cross link other related products on that web page and convert a sale. Great answer!
Yeah the other benefit i didnt mention is the page is another term you rank and pull traffic for, you would loose that entry point if the page was 301'd. Theses a chance traffic landing on this term may browse and purchase a related product, which is a sale you never would of made. I also trial Adsense on these pages, it doesnt detract from your product sales and if people are going to navigate away because you are out of stock they may as well leave via an ad and earn you some secondry revenue.