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2 hour side-project to 2 million visitors (gramfeed.com)
79 points by krisrak on Feb 28, 2012 | hide | past | favorite | 12 comments

Hardly a 2 hour side-project but, nevertheless, impressive.

NB: titlewise, the latter is being measured a year after the former was launched.

This is how you get traffic by the way. News website use this trick all the time.

Has the author of this app tried to monetize this?

Yes, it is monetized by Ads and affiliate programs from photo printing companies

Sorry to hi-jack the thread but I have a few AppEngine questions for you:

1) I don't understand their pricing scheme, does gamfeed use the free or the paid? (because currently I'm seeing 2 price lists: http://code.google.com/appengine/docs/billing.html and http://www.google.com/enterprise/cloud/appengine/pricing.htm...)

2) AppEngine Datastore: have you ever need to modify your model in a way you have to run a transaction over a large number of rows? If yes, would that hurt? (or, another case is if you had encountered a bug in your code that mistakenly recorded the wrong data thus you have to "clean them all").

3) I saw your code regarding code optimization, would that cause the code to become a bit brittle by not encapsulating the caching somehow? Like, spreading the cache at various level in your code.


1 - gramfeed is paid, http://code.google.com/appengine/docs/billing.html is correct, dont know what the other one is, i think that $9/month in minimun fee, i go past it anyway.

2 - datastore query is expensive but memcache works great, so cache frequently accessed data

3 - i make sure that whenever i put() any data, i immediately set Memcache, and before making any get() from datastore, I try get Memcache first, this should not cause issues.

Thank you for the reply!

My question for point #2 is in the line of the need to perform data migration actually.

Let's say you have a bug on your code in a way that the data stored currently are wrong and you need to fix them up by performing a batch update. Would that hurt you in terms of cost? How would you handle such situation?

Or let's just say that your user profile data model needs to be re-jiggered to support a new feature (adding columns, changing current columns, etc).

it depends on how big your data is, but every query operation, every fetch, every write operation it charged. http://code.google.com/appengine/docs/billing.html has details on how many read/write datastore API calls are made per operation. if u have to write in a new column for thousands of entries, then it will cost a bit, $0.10/100k operations, one re-write has 7 operations + incoming/outgoing bandwidth cost + instance usage cost will apply, it is hard to estimate actual cost.

Your other projects are impressive as well, are you a one man team for all of them? Also thanks for the insight, this info isn't commonly shared with other startups, I appreciate it.

yeah, one man team.

I'm surprised Instagram hasn't swooped in and purchased it to acquire the developer (talent acquisition). Obviously @krisrak has a tremendous grasp of the platform.

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