I am currently hosting a 30 day guest. It has been less than desirable...and it was IB, as I got the booking when I was nearly a brand new host and hadn't had many guests yet, so I didn't know better. Aside from the fear the guest may not leave and I will have to evict, I just never wanted a roommate. Hosting short term guests are easy because they are in and out and less chance of them sitting around living in my home the way a long term guest would. I agree with what the other woman said--run a background check on the prospect and take your time to make sure it's a good fit. Also really think about your house rules--even if you think it's common sense, put it down in writing so that way if something goes wrong you can say, "This is included in my house rules that you can't paint the ceiling black"....!
To answer your question about who you get for long term...I live in Las Vegas and we get mostly people moving here with no job trying to make a fresh start and it almost NEVER works out, so they end up hanging on for dear life to whatever they can. That's the kind I have in my house now..the old "I've just moved to town and am looking for work." Meanwhile they have figured out real quick it's not easy to find a job, their problems have followed them here and they are broke and can't even get enough cash together to move into an apartment. The flip side is we also get construction folks here in summer for long projects, lots of people here long term for meetings or work or conventions. If you live in a seasonal tourist town, I imagine your long term guest pool for seven or more days may be a lot more than you think. Just use caution. Long term guests will require being treated as a regular rental in most cities (here no matter if it's a day and they don't leave I have to follow the eviction process with the courts) so maybe do a little research. It might pay you better in the long run to just pay a higher insurance premium, bump your rate up to cover the increase and take all types of stays. Maybe bump your rate but for 30 day stays or longer give a big discount, so that will attract more long term guests...that way you can still have guests, cover your higher premium and see if you get any bites for long term guests.