Visit any online marketplace and the first thing you'll see in the Question & Answer section. Often the answer is 6+ months or long dated.

While this maybe an adequate description for some, as a consumer, you should demand to know the exact expiration date you will be purchasing.  Why?  Because the shorter the expiration date, the less test strips cost.  The value of test strips expiring in 3 months is far less than those expiring in 12 months.  

This is typically why they are being sold in a marketplace.  The seller is simply trying to get some money out of them before they expire.  In many cases, this means larger margins for the seller, because they can purchase the short dated strips for far less than normal long dated strips.  They then mark them up to normal price and pocket the difference.

As anyone who has shopped with us knows, we always show you the expiration date and the price for that expiration date before you purchase.  Normally the shorter the expiration date, the lower the price.  The added benefit of selling test strips this way is less returns, less complaints and happy customers, which is the way we like it!