To thank someone for their interest in you, it is best to know what kind of context this is in.
For example, what you would say to someone in a job interview is probably very different from what you would say if you are on a first date with someone. The method of communication could also influence what you say. In an email it would be appropriate to say directly,
- “Thank you for your interest in me” or “Thank you for your interest in learning more.”
When you are speaking, however, this sounds a bit too formal. Instead, when you are in a professional context, you could say something like
- “I appreciate your taking the time to meet with me.”
(Note that the grammatically correct usage is “your taking the time with me”, though many people will make the mistake of saying “you taking the time to meet with me.” Because it is in front of a gerund, you should use your, not you.) In other contexts, saying
- “Thank you for your time” or simply “Thank you”
is often enough.
When you are in a friendly or romantic context, it is often unnecessary to thank someone for their interest in you. This is implied, because if they are not interested in you they will not be spending time with you.
The best way to handle this is to actually compliment them or show interest in them instead. If you do think that thanking the person is necessary, you can use any of the phrases from above.