I have not promised future tuneups but have had followup conversations with several people I've sold bikes to, including someone who's called me twice looking for bikes for other family members. I can see what MJ's point is and maybe it's warranted but I am friendly to people who show up to buy a bike, tell them about it, what I've done, what it might need in the future, and so far that's gone pretty well. All but possibly one person who's shown up to see a bike have bought; no returns, no complaints, no hassles. ymmv obviously.