I'm on the fence on this one, as I agree partially with both points of view expressed. Yes it can be a waist of your time dealing with the free sites, and yes you can have too many unqualified leads taking up too much of your time. But it really depends on how you go about it, for instance, I use the free sites as somewhat of a filter I never give them my contact information on the free sites, just a way to respond back to the add via email, and I communicate with the generated leads via email in my spare time qualifying the leads that way until I am sure that it's actually worth my time, then after I acess that they want or need what I've got, I'll give them other avenues to contact me.
I can see that If you advertised your contact information on the internet free sites that you would be inidated with calls, emails ect that in the end 90% wont even pan out but in my situation I sell big ticket items so If I get one customer out of 100-200 emails in the end it's just generating another source of income for me, that only cost me 15 minutes or less every other day. Now if you sold items costing less than a few thousand dollars it might not be worth your time.
Example:
Last year I advertised a piece of property on Craigslist that I originally purchased two years prior for $115,000 this was 58 acres of raw land that I did nothing with, two years later I listed it on Craigslist for $250,000, after 6 months of emailing back and fourth I had my list of suspects down to three prospects, all three were interested, I showed it twice and got an offer of $226,000 from the second guy (which I accepted) making over $100,000 profit for myself just off of that one transaction. Would you consider that a waist of my time?
As long as you filter the craigslist to your advantage it could serve as a valuable reasource, just a thought.
Good luck to everyone whatever you decide.
~James