I would suggest that your reply may indeed be "Spammy."
Or, it could in fact be a "God send."
Same platform, same tweet. I'll explain...
First we should agree there are various interpretations of "immediate needs" that completely, and utterly change the dynamic of the reply.
For example, if you're a web designer and someone tweets that they need to redesign their website, well your reply will need to be much more relationship building in order to build a "know, like and trust" experience.
If you're a local plumber and someone locally tweets out a "stress-tweet" that they just spent the last hour plunging their toilet and there's no hope, well, your service offer would be far from spam... if service is your offer. :)
Consider the situation, then a reply to the effect of:
@xyz, so sorry for to hear. Saw your tweet & can be there in 30 mins to solve. Call me (Will) 555-555-5555. We'd be honored to serve.
Include a picture in the above of your business, or logo for credibility, and wait for the phone to ring.
Same would apply for a locksmith. Would you not consider that to be a God send to get a tweet offering to solve your immediate need in real time?
It can't be about sales, it needs to be about service, and solving problems or meeting the need in the moment.
Put the customer hat on, and ask what you would only WISH might show up if you tweeted something revealing a need for your service.
Now were cooking. Happy tweeting!
PS - excellent article recently I thought you'd be interested in where this very service was proven real time with a locksmith. Check it out: http://goo.gl/2TeSnv