William Hill have been running regular Risk Free Casino / Skill games offers most weekends. There is currently a £10 live casino risk free offer, where they will refund your losses to £10. I made £88 on this this weekend (8 accounts). How much you make depends on how you choose to play your £10.

Most deposit bonus reloads come by email. Ones to look out for on a semi regular basis are

BetClic (Usually £10 every 6 weeks or so)
Bwin (Usualy £4 every 2 months or so)
Expekt (Only if you set up an account BEFORE they excluded UK)
Coral (Casino Bonus every Wednesday)

There are also a number of offers I receive every week such as

IAS Bet, If your horse wins we'll double the winnings (16th Feb)
Centrebet, If your HT/FT Superbowl bet is winning at HT and loses we'll refund your bet. (Current)
Betfair 50% Of your stake back if one leg lets you down on a 6 nations triple (Expired as first game was last night)
etc.

All these offers can be profited from, but it's more complicated than straight forward matched betting. Also they are usually invite only, so no email no offer. The Betfair & Centrebet ones are available on site, check availability for your country before taking part.

The secret is to read the emails carefully. There are often offers tucked away and not in the main subject line. If you are emailed an offer and can't work out if it's viable, post it here. This not only benefits you but the whole board.

In 5 weeks it's the Cheltenham festival. I'm hoping for offers from Coral, Ladbrokes, William Hill, Paddy Power & Victor Chandler. You never know though