Almost never. If you send me an e-mail suggesting that I consider creating a certain type of file, I will politely reject your suggestion and remind you that I offer custom sessions. Taking a suggestion would not be fair to the many boys who pay full price for custom creations. Sometimes, however, I might issue a poll on Twitter asking for your vote on a type of file, etc. If you are interested in having your voice heard, make sure you watch for my rare twitter polls.