Since you're talking MSN and hotbot you're talking Inktomi, and you can find Ink in Forum 1, you should spend some days there:
The big, eternal debate over whether Ink treats pages differently depending if you paid for them to be spidered (and re-spidered every 48 hours), or if they just got crawled and spidered for free - is still ongoing it looks like to me.
The nice thing about a few pages PFI (pay for inclusion) is you can practice optimization for Ink and check your tweaking in a few days rather than waiting maybe months to see if you've changed in the serps - the better thing is when you've figured how to make a page for Ink you can make good pages and pay (quite cheaply I think) to get your name in lights very quickly, and get traffic.
Ink goes up and down they say - I hear Google does too sometimes ;) - they all do
Ink is old news, but it's also brand new news because of all the associated things - MSN sends 24% of SE-driven shoppers to the Web, now Yahoo is starting to run Ink results, Microsoft will drop Ink and go with MSNBot soon - what happens to Looksmart, what about Overture placements, all of these questions and more.
So it's worth following, and IF Ink remains straightforward to optimize for, that suddenly opens up Yahoo...