In my AD&D days my players spent a lot of time in the city of Grey Hawk. Their favorite hangout was the Nights End Tavern. Over the 20 year campaign (5 years real time), they came to own their own shops and homes within the City. Lola a serving wench, provided the players with both information, and romantic interludes, both male, and female players alike. Unknown to them she cleaned lots of information from them, and that information caused loads of trouble for them through out the years. For as provocatively beautiful as she was, she was a master spy, and thief for the Thieves Guild of Grey hawk. The players unknowingly made her one of the richest people in the city. (And they never found her out.