If JS is disabled, it shows an unstyled page with text "Please wait".

Would make sense to make it downgrade nicely, at the very least for the landing page.

Is a single page app. Need JS.

Minimally tell them that js is required?

But you could have a static landing page that leads to your single page app in the future.

my 2 cents from a quick glance: don't require users to login to use the site, let them at least search or find products.

I can't send price changes alerts if I don't have user email

Why do you need a username and password though? You could simply just provide the product and the price. Then email that user when the price changes. Offer a one time unsubscribe link in that email if they wish to not receive further updates.

Think newsletter with product price changes.

You could wait to collect the email address until after users have searched for a product and found something they want an alert on. That way people know what they're getting into and it makes more sense why you need their email address.

Thanks for feedback but we want to add an interactive demo on first page.

Which online stores? All of them?

I'm the founder of http://pricify.com and we've had several iterations of the product and focusing on various experiments. Currently we land users on a landing page and thats a test we've been running for a while, but we've also had it where products are listed upfront with infinite scroll. Both seem to achieve hit different goals.

We've spent a long time establishing landing page messages so it makes sense to users as soon as they get there - otherwise they just bounce, including HN users! I've not signed up to try this out, but there is just not enough info before asking a visitor to sign up. So may want to add some info there on the value prop?

Thanks, now we have a print screen on the first page (quick version).

It seems that this is a new trend. Shoptagr, Pricify and others. Also, this one looks really unappealing.

I'm the Co-Founder and CEO of http://Shoptagr.com and one of the biggest challenges for us has been to track item's prices at the SKU level, size, color and more, which is essential for the "the smart savvy shopper".

(Amazon) affiliate things like these seem like nice zero work, long tail side income projects. I want to make one on my own some day.

Was working one of these last year -- never launched, but it's pretty much good to go.

If you're in the UK (my target market), give it a go! http://salr.io/

I built a similar tool: http://skanout.com/

It's less of a price alert but rather notifying you if we can get you the price you want or not.

UPDATE: Demo on first page + change password functionality

camelcamelcamel.com for Amazon products is pretty nifty

I have used https://pricenoia.com/ to compare prices between different Amazon sites and alert me of price drops

for price changes i use camelcamelcamel.com, it works like swiss clockwork

This works only for Amazon. Our app is generic

I think the point is 'works like clockwork'. And as the other user said, I'm not prepared to test out your service if you require a registration and sign in before I can see anything about it.

There is also http://camelegg.com for Newegg

Those 2 sites are probably the most I purchase from, however generic is nice for the other non-popular stuff!

Another cool addon is Hoverhound: https://addons.mozilla.org/en-US/firefox/addon/newzon/ I can see how low it has ever been vs just a price drop, and it prevents me from buying on newegg when it sees a lower price on amazon