The problem is that Twitter's filtered Streaming API has quite a small limit on the number of words that you can provide to match tweets. So, it would be impossible to scale.

A better option might be retrieving tweets from the Firehose Streaming API, but one would need a massive backend to handle it. Additionally, access has to be requested to Twitter and it's very rarely granted. Alternatively, Datasift or Gnip can be better sources for the firehose, but I think they only provide a fraction (like 1/10) of the real amount of tweets that go through the actual firehose.

The Twitter Streaming API allows you to track up to 400 keywords. For most businesses, that seems like enough. Or if you need 1000, you simply need 3 accounts.

Asking out of curiosity Is it legal to automate tweet in twitter? I mean if twitter detects someone is doing so wont they ban them?

Edit: I Read the post properly the replies are manual not automatic so I don't twitter will have any issue with it.

It might be ok to automate tweets, but this particular service might run afoul of Twitter's spam rules

Per Twitters Rules for Identification of Spam[1]

-If your updates consist mainly of links, and not personal updates;

-If you send large numbers of unsolicited @replies or mentions in an aggressive attempt to bring attention to a service or link;

[1]https://support.twitter.com/articles/18311#

It's acceptable to automate twitter activity per the rules here: https://support.twitter.com/articles/76915

I'm already a fair way into building a similar paid tool (curated engagement via twitter+disqus), if its something you might want to try out ... email in my profile.

It's something I've thought about and both our current investors and potential future investors have mentioned that this could be a product on its own. If I were to scale it up and turn it into its own startup I'd want to make sure not to saturate the tweetosphere with it or there's no benefit over the competition. I'd also probably license it out to early stage startups instead of bigger companies because no one wants to be spammed to by the next HP, Apple or Dell computer when you ask for suggestions from friends.

A similar product exists : http://launch.c4chq.com/

Also a YC startup called InboxQ just shows you the questions to let you manually respond.

Thanks @jaredsohn . I wonder how I can get in touch with them.

I have been trying to preview it, but the it get stuck after Enter keywords. https://www.dropbox.com/s/jr3kkq1x4p6wf3q/Screenshot%202014-...

If you click on "Help" on their webpage, it takes you to a getsatisfaction page: https://getsatisfaction.com/inboxq