Recently, we've had a couple of ill-received questions that asked for shopping advice:
Warm jacket with several pockets for travel: suggestions?
Travelling to the Kruger National Park
Both of these were arguably more on-topic for travel.SE, and both (in their original forms) asked for shopping advice.
The first one asked for people to recommend a jacket with certain features. It was originally migrated here from travel.SE and then bumped back to them. It also received a message saying, "Questions seeking price-shopping assistance are off-topic because they tend to become obsolete quickly. Instead, describe your situation and the specific problem you're trying to solve," with a link to an SO blog.
The second one smelled a bit spammish. It asked for price-comparison shopping on plane tickets, and it linked to what appeared to be the OP's own blog. Asking for recommendations on what item to purchase is off topic here. After some edits, the question did receive an answer, which I upvoted and learning interesting things from. The OP never came back, which may be because they were spamming or because they were insulted by the heavy downvoting.
This came up previously in meta, but nothing seems to have happened. Almost none of the people involved in that discussion seem to be active here anymore, possibly because of the Monica Cellio affair.
Can we improve on this situation?