This guy has some interesting stats and trends. His record (won/lost) varies, but he has a twisted sense of humor. He also posts historical stat data, which is quite interesting but as always should be taken with a grain of salt.
http://walterfootball.com/
Last year I bet on-line (with Bet365) and ended up making a small profit, about 20% on top of my original investment.
A few years back I played pro-line and believe it or not, usually came out ahead. I would play about $50/week on $5 & $10 selections. The most I won in a single bet was around $500, but quite often I would win with a 3 team point spread ($50) that would cover my costs for the week.
I did come very close to winning the "Pro-Picks" missing out by one game (nice payout both times of $100-$200K). I still play that ticket, usually picking my batch of favorites and then selecting or boxing a long shot. If all favorites win, the payout is very low so it is best to try to hit a win with a long-shot (like Arizona last week). A couple of years back a few of us from work would pool our cash and play the Pro-Picks and box 4 events. We won a couple of times when all favorites came through. Unfortunately I have been consulting lately and do not have a social group to pool funds with (easier to play 4 boxes when you don't have to dish out $80/ticket).
If I made a living on betting I would no doubt be investing tons of time into stat analysis, etc. But for $50/week, it is cheap entertainment.