It's not ok if someone is using chat just to spam for tips! It's not nice to ask for tips, even if you do it only once! If someone is willing to share some chips he will do that, but asking someone to do it looks ugly in my opinion! I believe this "tip me/share some money/make rain/...." just bothers all the players!
Play with what you have, have fun... sometimes discussions can be very interesting, participate... and sometimes big winners will share some chips because they are happy! It's how I do, and believe I have a lot of tips/rains behind! Of course, where I am active!