You know those price alert emails (NASDAQ:AMZN) sends you every time there's a deal on something you've browsed? Pinterest wants a piece of that action.

Pinterest wants to be your shopping go-to. Source: Pinterest.

Last week, the visual network announced a feature that allows users who've pinned a for-sale item to their feed to be alerted when the price drops. "Product" pins take visuals from certain websites that allow Pinterest to also see price data. Nordstrom and Wal-Mart are among the bigger-name retailers to support product pins as of this writing.

Therein lies the problem for Amazon stock investors. Pinterest's deep-pocketed allies have as much or more to gain from seeing the e-tailer disrupted.

Yet the plan isn't without holes. Pinterest may have emerged as one of the more important social networks but Instagram still has a huge following while Yahoo!'s (NASDAQ:YHOO) social additions to photo sorter Flickr saw a 50% increase in uploads shortly after the latest release in June. Pinterest needs to do more to stand out. Taking on Amazon will achieve that, but at what price?

If Pinterest has a built-in advantage it's that iPad users love the service. Roughly 50% of social activity on the device runs through the image-driven social network, according to ShareThis. I suspect a good chunk of that activity is generated by shoppers posting pictures of recent buys or wants. Real-time price alerts could add up to huge savings for these sorts of consumers, which, in turn, would allow Pinterest to get even deeper hooks into them.

Expect Amazon to respond. How? I'm not sure, so I'll put the question to you: What would you do about Pinterest's plan if you were Amazon CEO Jeff Bezos? Leave a comment with your best ideas, and then tell us whether you'd buy, sell, or short Amazon stock at current prices.