Start with the licence, not the bonus headline
Licensing is the one check that cannot be skipped, because it tells you who stands behind the games and which rules you play under. PlayOJO is listed with UK Gambling Commission and Spelinspektionen, so two schemes are in play, and each licence has its own number: 039326-R-319358-061 for the UK Gambling Commission and Kommersiellt online 710307439 for Spelinspektionen. The operating company is Skill On Net Limited and the headquarters country is CY.
7777 MD sits in a different regulatory picture. Its regulators are S.A. Loteria Națională a Moldovei (state monopoly) and Agenția Servicii Publice (general rules, 25.06.2019), its legal entity is NGM Company SRL and its headquarters country is MD. Knowing which authority supervises a site, and being able to look its name up before you deposit, is the single most useful habit when you compare bingo sites. The Bingo sites rankings let you line operators up side by side on this point.
Read the bonus as a set of terms, not a headline number
A welcome offer is only worth what its conditions say. 7777 MD uses a welcome bonus structure with a 200% up to 2000 MDL + 200 free spins, new users and a match of 200%, and it also offers cash out. PlayOJO runs a welcome bonus too, with a 50 free spins (UK) attached to a free bet offer.
The number that decides whether an offer is usable is wagering. PlayOJO lists wagering of 0, so the free spins carry no play-through requirement, while 7777 MD does not list one in the same way, so a large match there needs a closer read of the bonus terms. A big headline with strict conditions can be worth less than a modest offer you can use straight away. The 7777 MD review and the PlayOJO review set out how each offer is structured.
Check the minimum deposit against the payment methods you actually use
The smallest useful deposit tells you whether a site is practical for your own budget. 7777 MD sets a minimum deposit of MDL 10, while across the bingo sites in the data the minimum deposit spans €1 to €25. A site with a low entry point is easier to test, and a site that only suits large deposits narrows who it works for.
Payment methods decide that in practice. 7777 MD accepts a wide domestic and card list through Qwallet, Bpay wallet and RunPay wallet, covering wallets, bank transfer and mobile payment options, which suits players who pay in local ways. PlayOJO takes debit cards and eWallets, so a player who only holds a card or a wallet has a narrower route in. Both operators also list a mobile app under fast payouts and mobile app and fast payouts and mobile app.
Confirm the site is actually a bingo site
Bingo is the product you are here for, so check the product list rather than the total game count. 7777 MD offers lottery and bingo, which pairs bingo with lottery products, and PlayOJO lists bingo.
Around the bingo category the other options worth reading sit alongside these two: Mecca Bingo and bingoplus for the bingo side, Svenska Spel and Camelot / The National Lottery for state-backed operators, and paf, Wplay and Coral for wider range. Each review covers the same criteria, so the comparison stays fair.
Look at game variety and providers as a secondary check
A broad lobby is pleasant, but a bingo player cares most about the game list and the studio behind it. PlayOJO lists slots, live and table, live dealer games are available, and its lobby draws on Peter Sons, Amusnet and Big Time Gaming, including Slingo among the names. 7777 MD also covers sports markets through football, basketball and tennis with a bookmaker setup, which is a different shape of site again.
Finish with safer play, and keep play for adults
Safer play tools are the part many readers skim, so weigh them early. PlayOJO offers deposit limits, cool off and self exclusion, which is a fuller set covering deposit limits, a cool-off period, self-exclusion and reality checks. 7777 MD lists deposit limits and cool off, and identity checks are required before you can play. Support matters too when a limit needs setting: both brands reach you through email, chat and phone and email, chat and phone.
Play is for adults only. Decide your deposit and session limits before you start, use the tools listed above if they help, and treat any offer as a reason to set a budget rather than a reason to raise one. If gambling stops feeling like entertainment, step away from the site and seek support in your country.